CN112008248B - Method for generating surface pattern track by laser double scanning strategy - Google Patents
Method for generating surface pattern track by laser double scanning strategy Download PDFInfo
- Publication number
- CN112008248B CN112008248B CN202010743519.4A CN202010743519A CN112008248B CN 112008248 B CN112008248 B CN 112008248B CN 202010743519 A CN202010743519 A CN 202010743519A CN 112008248 B CN112008248 B CN 112008248B
- Authority
- CN
- China
- Prior art keywords
- scanning
- curve
- pattern
- point
- straight line
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 36
- 230000008569 process Effects 0.000 claims abstract description 14
- 239000002344 surface layer Substances 0.000 claims abstract description 10
- 238000003754 machining Methods 0.000 claims abstract description 6
- 239000011159 matrix material Substances 0.000 claims description 14
- 230000001133 acceleration Effects 0.000 claims description 11
- 238000010408 sweeping Methods 0.000 claims description 9
- YTCQFLFGFXZUSN-BAQGIRSFSA-N microline Chemical compound OC12OC3(C)COC2(O)C(C(/Cl)=C/C)=CC(=O)C21C3C2 YTCQFLFGFXZUSN-BAQGIRSFSA-N 0.000 claims description 4
- 238000012512 characterization method Methods 0.000 claims description 2
- 230000002093 peripheral effect Effects 0.000 claims description 2
- 238000012163 sequencing technique Methods 0.000 claims 1
- 230000009469 supplementation Effects 0.000 claims 1
- 230000004044 response Effects 0.000 abstract description 3
- 238000005530 etching Methods 0.000 abstract description 2
- 230000008901 benefit Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005520 cutting process Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 240000007594 Oryza sativa Species 0.000 description 1
- 235000007164 Oryza sativa Nutrition 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000010329 laser etching Methods 0.000 description 1
- 238000004093 laser heating Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 235000009566 rice Nutrition 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K26/00—Working by laser beam, e.g. welding, cutting or boring
- B23K26/36—Removing material
- B23K26/362—Laser etching
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1602—Programme controls characterised by the control system, structure, architecture
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
- B25J9/1656—Programme controls characterised by programming, planning systems for manipulators
- B25J9/1664—Programme controls characterised by programming, planning systems for manipulators characterised by motion, path, trajectory planning
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Robotics (AREA)
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Plasma & Fusion (AREA)
- Automation & Control Theory (AREA)
- Numerical Control (AREA)
Abstract
本发明采用激光双扫描策略加工表层图案轨迹生成方法属于激光加工轨迹规划技术领域，涉及一种采用激光双扫描策略加工表层图案轨迹生成方法。该方法通过对图案划分外区和内区，并分别采用环扫和行扫的扫描策略。首先确定外廓曲线最小曲率半径及其位置，计算由图案轮廓曲线及机床动态性能限制的外区宽度，并与扫描行距匹配。以图案轮廓等距偏置线划分图案为内外区，图案廓形为拼接曲线时内外区分界线还需去自交处理。以扫描行距等距偏置图案轮廓生成外区环扫轨迹，对拼接曲线环扫轨迹时进行自交处理。经去自交处理后轨迹间无交叠，避免实际激光加工中局部过烧。保证扫描速度能够满足机床动态响应能力，所生成加工轨迹与刻蚀图案边缘平滑。
The invention adopts a laser double-scanning strategy to process a surface layer pattern track generation method, belonging to the technical field of laser machining track planning, and relates to a surface layer pattern track generation method using a laser double-scan strategy. The method divides the pattern into an outer area and an inner area, and adopts the scanning strategy of ring scan and line scan respectively. First, determine the minimum curvature radius of the contour curve and its position, calculate the outer area width limited by the pattern contour curve and the dynamic performance of the machine tool, and match it with the scanning line spacing. The pattern is divided into inner and outer areas by the equidistant offset line of the pattern outline. When the pattern outline is a splicing curve, the boundary line between the inner and outer areas needs to be self-intersecting. The outer-area ring-sweep trajectory is generated with the equidistant offset pattern contour of the scanning line, and the self-intersection is performed when the curved ring-sweep trajectory is spliced. After the self-intersection treatment, there is no overlap between the tracks, which avoids local overburning in actual laser processing. Ensure that the scanning speed can meet the dynamic response capability of the machine tool, and the generated processing track and the edge of the etching pattern are smooth.
Description
Technical Field
The invention belongs to the technical field of laser processing track planning, and particularly relates to a method for generating a track of a surface pattern processed by adopting a laser double-scanning strategy.
Background
Surface patterns are used as key features of parts such as circuit boards, fine sensors, radio frequency antennas and the like, and are prepared by adopting a precise special processing technology of laser processing in recent years due to extremely small thickness and extremely high precision. The laser is easy to integrate with the multi-axis machine tool and the processing mode is similar to milling processing, a single scanning track (ring scan or line scan) generated by the general CAM software can meet the coarser processing condition, and some special laser processing CAM software only provides a drawing interface and adapts to a control function, and the generation logic of the scanning track is not substantially changed. Under the increasing demands for high-precision and high-efficiency machining, a single laser scanning strategy exposes huge defects: the annular scanning processing mode can ensure the smoothness and quality consistency of the edge of a processed pattern, but a curve segment with a rapidly changing curvature is generated along with the shrinkage of a scanning track towards the inside of the pattern, and the actual scanning speed of the laser cannot reach the programming speed under the limitation of the dynamic performance of a machine tool, so that overburning is caused; the line scanning processing mode has simple movement and good speed accessibility, can avoid the sharp change of the scanning direction, but the pattern edge presents serious saw-tooth shape due to the over-dispersion of the spot position on the pattern edge. Therefore, the circular scanning track and the line scanning track are reasonably combined, the edge quality and the processing efficiency of surface area laser processing can be effectively considered, but the different scanning tracks generated by partitioning are difficult to realize in the existing CAM software, the flexibility is poor, and the fine processing requirement of local tool location adjustment is more difficult to meet. Therefore, the method for generating the laser double-scanning strategy processing track of the surface layer pattern is developed, and has important significance for manufacturing parts taking the surface layer pattern as a key functional structure.
Zhanfei Zhang et al, published in Optics and Laser Technology, volume 121, 105834, Investion on geometry prediction and surface quality of microorganisms engineered by ultra fast Laser, tried to use a linear plus circular scanning strategy in the circular domain, and obtained a certain edge quality improvement effect compared to completely using a linear scanning strategy, but only one circular scanning track, the edge quality still affected by linear scanning, and further research on the dual scanning strategy track generation theory of the circular domain or complex patterns was not carried out, so that the shortcomings still exist. Michael contrast-Saenz et al, published in the book "Laser alignment: Advances in Research and Applications" Chapter 4 "PCB-MEMS: simulation of Active Microfluidic Devices by Laser alignment", describe a method for removing the unreserved region of a metal pattern, which comprises dividing the geometric pattern and the unreserved region by circular scanning, cutting the unreserved region into a series of strips by line scanning, finely processing the designed contour, and finally removing the strips by Laser heating with an air knife. The method is more suitable for a cutting process, the preparation of a surface pattern can cause overburning due to the secondary scanning processing of the outline, the dynamic performance of a machine tool is also considered, and in addition, the automatic generation of two scanning tracks in different regions is not involved, so that the method has limitations.
Disclosure of Invention
Aiming at the defects and limitations of the prior art, the invention discloses a track generation method for processing a surface layer pattern by adopting a laser double-scanning strategy, which can ensure that the scanning speed of the track inside the pattern meets the dynamic performance constraint of a machine tool and also can meet the requirement of the consistency of the processing quality of the edge of the pattern by dividing the pattern into an outer area and an inner area and respectively adopting scanning strategies of ring scanning and line scanning, and the generated processing track and the edge of an etched pattern are smooth, and the local tool location point adjustment which is usually required in precision processing is easy to realize.
The technical scheme of the invention is a track generation method for processing surface layer patterns by adopting a laser double scanning strategy, which is characterized in that the method divides the patterns into an outer area and an inner area, and respectively adopts scanning strategies of ring scanning and line scanning; firstly, the geometric parameters of curvature radius, unit normal vector, concave-convex direction and the like of each point of the pattern contour curve are calculated by the pattern contour curve, and the minimum curvature radius and the position of the pattern contour curve are determined. Secondly, determining the maximum outer area width limited by the pattern contour curve and the machine tool limit processing capacity, matching the outer area width by combining the scanning line spacing condition, dividing the pattern into an inner area and an outer area by using the equidistant bias line of the pattern contour, and performing selfing treatment of the inner and outer boundary lines for the complex pattern with the contour being the splicing curve. Then, equidistant bias is carried out on the pattern contour to generate an outer zone circular scanning track, and for the complex pattern with the contour being a splicing curve, selfing removal processing of the circular scanning track is also needed. Finally, a series of linear sets which are arranged at intervals of scanning line intervals and cover the inner area are generated, and the parts of the linear sets, which are positioned outside the inner area, are calculated and removed, so that the inner area scanning track is generated. The method comprises the following specific steps:
step 1, calculating curve-related geometric parameters from the pattern outline curve
For example, when the profile curve c (t) is given by the parametric equation (x ═ x (t), y ═ y (t), and z ═ 0), when moving in the clockwise direction along c (t), the unit tangent vector is:
additionally setting unit vector
The unit normal vector pointing to the inside of c (t) is:
the first derivative, the second derivative and the curvature radius of C (t) are respectively:
the direction of the second derivative vector of a certain point on the curve is the same as the direction from the point to the center of the osculating circle, so that the concave-convex direction of the curve section of the neighborhood of the point is reflected. The second derivative vector of C (t) is calculated as follows:
then according to
And
establishing curve concave-convex direction judgment parameters according to the difference of the directions:
wherein dir (t) ═ 1 indicates that the point neighborhood curve segment is in a convex shape, if dir (t) ═ 1 indicates that the point neighborhood curve segment is in a concave shape, and if dir (t) ═ 0 indicates that the point neighborhood curve segment is in a straight line segment. The minimum radius of curvature of C (t) is expressed as:
ρmin＝min{ρ(t)}＝min{min{ρ(t)}|dir(t)＝1，min{ρ(t)}|dir(t)＝-1} (8)
wherein min { ρ (t) } memorydir(t)＝1And min { ρ (t) } counting the cellsdir(t)＝-1C (t) minimum radius of curvature of the convex portion and the concave portion, respectively.
Step 2, dividing the pattern into an inner region and an outer region
On the basis of calculating all the geometric parameters of C (t) in the step 1, carrying out equidistant bias on C (t) to obtain an equidistant bias line, namely an expression form of an inner and outer distinguishing boundary line of the pattern:
wherein d isNIs an equidistant bias line Cd(t), i.e., the outer region width of the pattern.
And CdThe radius of curvature of (t) is expressed as:
ρN(t)＝ρ(t)-dir(t)dN (10)
the above formula indicates that for the curve segment concave upward in C (t), Cd(t) the radius of curvature of the corresponding location becomes larger, and for the convex curve segment on C (t), Cd(t) the radius of curvature of the corresponding position becomes smaller.
When C (t) is a first-order continuous curve
If ρmin＝min{ρ(t)}|dir(t)＝-1That is, when the minimum curvature radius of C (t) is located at the concave part and C (t) has the convex curve section, the constraint of the dynamic performance of the machine tool is relatively easy to satisfy only by Cd(t) minimum radius of curvatureRho or moreminThe accessibility of the scanning speed of the whole outer area can be ensured. The maximum outer region width is obtained from equations (8) and (10):
dN＝min{ρ(t)}|dir(t)＝1-ρmin (11)
if ρmin＝min{ρ(t)}|dir(t)＝1That is, when the minimum radius of curvature is located at the convex portion, the machine tool limit machining capability determined by the machining parameters and the machine tool parameters needs to be considered. For the linear interpolation motion, micro-line segments approach to curve segments, the scanning speed in each micro-line segment undergoes the processes of acceleration, uniform speed and deceleration, and the acceleration and the planned scanning speed of the machine tool are respectively expressed as a and v0Then the velocity increases from 0 to v0When in use, is v0A is calculated. The more the time proportion of the uniform motion is, the smaller the influence of the acceleration/deceleration stage on the whole processing quality is, the limit processing capacity of the machine tool is defined when the acceleration and deceleration motion distance accounts for the total motion distance 1/10, and the influence of overburning generated in the acceleration/deceleration stage can be ignored. The minimum linear scan distance is then expressed as:
in actual processing, v is planned0The curvature constraint of the pattern profile curve needs to be met with sufficient margin.
Because the approximated curve segment with small arc length can be regarded as a circular arc shape, and the radius of the circular arc is rho, and the chord height error is epsilon, the chord length s needs to satisfy:
the maximum outer region width at this time obtained from equations (10) and (12) is:
outside the above-defined patternThe zone width is only sufficient for machine tool dynamic performance requirements and does not allow for matching with the scan line spacing. Recording the line sweeping distance of the outer region as dcirAnd selecting the number of the circular scanning tracks which can be accommodated by the outer area according to actual needs as follows:
where INT (-) is a floor function. The outer zone width and the inner and outer zone boundary line equations matched with the circular sweep distance are obtained by the equations (9) and (15):
② when C (t) is formed by splicing curve segments
For each curve segment forming C (t), calculating according to the formula (i) and taking the minimum d in all the curve segmentsNThe value is obtained. In addition Cd(t) selfing also occurs at locations corresponding to the vicinity of the first-order discontinuity in C (t), to avoid Cd(t) the effect of local loop closure should be subject to a de-selfing treatment. Uniformly dispersing C (t) into n points and calculating according to the formula (9) to obtain CdDiscrete point set form of (t):
P＝{P1,P2,…,Pk,…,Pn},Pk＝(xk,yk) (17)
wherein x iskAnd ykAre respectively a point PkThe abscissa and the ordinate. Thus Cd(t) is approximately represented by a set of micro-straight line segments, i.e., PP ═ P1P2,…,PkPk+1,…,Pn-1PnGet curve Cd(t) from the intersection point, the point is converted into the intersection point of the two straight line segments. For any line segment PkPk+1The linear equation is as follows:
then any point P in Pm＝(xm,ym) To line PkPk+1The distance of (a) is:
for the numerator of the right side partial expression of the middle number of the above expression, if the absolute value operation is not carried out, the positive and negative of the numerator represents PmRelative to the straight line PkPk+1The position of (2): a value of 0 indicates that the point is on a straight line, and a value of positive and negative indicates that the point is on different sides of the straight line, respectively. It is referred to as a characterization point PmTo the straight line segment PkPk+1The parameter of the relative position is denoted sgn (d)mk) If two intersected straight line segments exist in the PP, two end points of one straight line segment are distributed on different sides of the other straight line segment, namely the product of relative position parameters of the two end points to the other straight line segment is determined to be-1. On the contrary, only if the product of the relative position parameters of two adjacent points to a certain straight line segment is-1, two straight line segments determined by the product are possible to intersect. In order to establish the criterion of intersection of certain two straight line segments in PP, the following matrix is constructed:
wherein, the value of each element of M is one of {0,1, -1 }. Straight line segment PmPm+1And straight line segment PkPk+1The essential conditions for the intersection are:
Mmkand MkmPositions in the square matrix M are symmetrical about a main diagonal, and a self-crossing discrimination matrix of the curve is constructed:
Inter＝M+MT+2A (22)
wherein A is a matrix in which all of the elements of (n-1) × (n-1) are 1. Then the element with the value of Inter being 0 is the intersectionI.e. the position of the curve from the intersection point. Suppose a straight line segment PmPm+1And straight line segment PkPk+1Intersect, and m < m +1 < k +1 (selfing occurs in a local small region), then the equation corresponding to the two lines can be derived from the intersection point Pmk＝(xmk,ymk) The coordinates of (a) are:
special cases are as follows: when x ism+1＝xmAt a time there is
When x isk+1＝xkAt a time there is
The set of curve points after selfing and replenishment of the self-intersections is:
step 3, generating a circular scanning track of the pattern outer area
The circular scanning track of the pattern outer region is obtained by equally offsetting the pattern outline curve C (t). When scanning from the outside to the inside of the pattern, the curve equation of the ith circular scanning track is as follows:
in addition, when c (t) is formed by splicing curve segments, the circular scanning track is also selfed, and since the selfed scanning track causes a part of the processing area to be irradiated with laser for multiple times, thereby deteriorating the processing quality, and even causing distortion of the scanning track profile, the circular scanning track needs to be selfed according to the processes of equations (15) to (23).
For generating an intra-region sweep trajectory in a scientific computing software environment, the basic idea is to first define the position of the peripheral sweep trajectory from the trajectory generation region, and then generate a series of sets of straight lines L ═ L { L that cover the trajectory generation region at the desired scan line spacing1,L2,…,Lj,…,LrAnd finally, rejecting the part of the straight line outside the track generation area.
To determine L1And LrWhen the scanning direction k is selected according to actual needsLAfter tan θ (θ is the angle between the scanning direction and the positive direction of the x-axis), any point P in the passing point set P is determinedk＝(xk,yk) And the slope is kLHas the linear equation of y-yk＝kL(x-xk) The intercept of the horizontal axis is easily known as:
selecting P points that minimize and maximize the intercept of the horizontal axis (when there are a plurality of corresponding points, C is describedd(t) a slope of kLThe straight line segment of (1) is only required to be selected as a point satisfying the condition), and is marked as Pq1＝(xq1,yq1) And Pq2＝(xq2,yq2) Special cases when theta is 0 DEG, Pq1And Pq2Respectively taking Cd(t) the uppermost point and the lowermost point, and P when θ is 90 DEGq1And Pq2Respectively taking Cd(t) leftmost point and rightmost point. L is1And LrShould be respectively associated with Pq1And Pq2Keeping a certain distance to avoid the line scanning track length being 0 or the circular scanning track and the line scanning track being coincident, wherein the distance is taken as the line distance d required by the internal region line scanninglineThen, the number of sweeping tracks that the inner area can accommodate is:
and the fine-tuning back row sweeping track line spacing of the whole inner area with the uniformly distributed row sweeping tracks is as follows:
further, the set of straight lines L ═ L1,L2,…,Lj,…,LrThe jth line scanning track L in thejThe equation of the straight line of (1) is:
consider next deleting the portion of L that lies outside the area within the pattern. For linear scanning only two end points of the scanning path need be determined, i.e. LjAnd Cd(t) intersection point. To determine the intersection point, LjDispersed as uniform point set Qj＝{Q1Q,Q2Q,…,QuQ,…,QtQ},QuQ＝(xuQ,yuQ) (discrete points ensure coverage of the inner region of the pattern and at most one L exists between two adjacent pointsjAnd Cd(t) intersection), the straight line segment set QQj＝{Q1QQ2Q,…,QuQQ(u+1)Q,…,Q(t-1)QQtQAny straight line segment Q inuQQ(u+1)QAll satisfy the equation of a straight line described by equation (29), so that LjAnd Cd(t) solving for the intersection points translates to QQjAnd judging the intersection of the straight line segment in the PP and solving the intersection point. Is easy to know QjAny point QuQ＝(xuQ,yuQ) Straight line segment P to PPkPk+1And any point P in Pk＝(xk,yk) To QQjMiddle arbitrary straight line segment QuQQ(u+1)QThe distance of (a) is:
in the above formula duQ→kAnd dk→uQThe absolute value sign of (1) is judged to be positive or negative and respectively recorded as sgnuQ→kAnd sgnk→uQWhich characterizes the relative position of the point to the straight line segment. The following matrix was constructed:
then straight line segment QuQQ(u+1)QAnd straight line segment PkPk+1The necessary conditions for sufficient intersection are as follows:
structure QQjAnd the PP intersection discrimination matrix is as follows:
wherein A is a matrix in which all of the elements of (t-1) × (n-1) are 1. Then Inter2The element with a median value of 0 indicates the number of the straight line segment where the intersection occurred, assuming Inter2When (u, k) is 0, a straight line segment Q is indicateduQQ(u+1)QAnd straight line segment PkPk+1Crossing, the intersection Q can be obtained from the equation of two straight linesuQ,k＝(xuQ,k,yuQ,k) Namely, the coordinate of one knife position point of the line scanning track is as follows:
in which, when theta is equal to 90 degrees in special cases,
when x isk+1＝xkWhen is, QuQ,k＝(xm,yuQ+kL(xk-xuQ))。
Complete solution of LjAfter scanning the locus knife position on all the lines, Q is addedjThe inner points are replaced with the desired tool location points and sorted in the scan direction. In addition, in order to reduce the total idle stroke, the sequence of the tool positions needs to be reversed for the odd or even numbered tracks in the line set L.
The invention has the obvious effects and benefits that aiming at the problem that the single circular scanning/line scanning processing mode in the surface area laser etching process cannot give consideration to the processing quality and the processing efficiency, but the existing CAM software is lack of the problem that the processing pattern generates the laser scanning track in the automatic area division manner, the pattern is divided into an inner area and an outer area, and the scanning track of the corresponding area is analyzed and geometrically calculated, the invention provides the track generation method for processing the surface layer pattern by adopting the laser double scanning strategy, so that two scanning tracks with advantages, namely circular scanning and line scanning, are automatically generated in the pattern, and the tracks are not overlapped after the self-cross treatment, thereby avoiding the local overburning in the actual laser processing. The scanning speed can meet the dynamic response capability of a machine tool, and the generated processing track and the edge of the etching pattern are smooth. The requirement of consistency of the processing quality of the pattern edge is met, and flexible implementation conditions are provided for the adjustment requirements of some local cutter location points.
Drawings
FIG. 1-flowchart of the overall process.
FIG. 2-a pattern of a contour curve formed by stitching together a first segment, a second segment, and a third segment of an elliptical arc.
FIG. 3-demarcating the inside and outside of the pattern without selfing treatment.
FIG. 4-boundary line for distinguishing inside and outside of pattern subjected to selfing treatment
Figure 5-generation of the out-of-pattern area loop scan trajectory without selfing treatment.
FIG. 6-Generation of the out-of-pattern area circular scan trajectory by the selfing process.
FIG. 7-preliminary generation of sweep trajectories covering regions within a pattern.
FIG. 8-scan locus generation within a pattern with excess segment removal.
Detailed Description
The detailed description of the embodiments of the invention is provided with reference to the accompanying drawings.
In view of the advantages of the ring scanning strategy and the line scanning strategy when surface patterns are processed by laser, the existing CAM software is difficult to automatically generate different types of scanning tracks by regions and adjust local tool positions, and is not beneficial to surface laser processing and high precision and high efficiency. Aiming at the situation, in order to realize the automatic and flexible generation of the scanning track suitable for the laser processing of the surface layer pattern, the invention provides the track generation method for processing the surface layer pattern by adopting the laser double-scanning strategy, and the whole flow is shown as the attached figure 1.
By taking a pattern formed by splicing a first section, a second section and a third section of elliptical arcs of a contour curve as an example, the implementation process of the invention is explained in detail by MATLAB software. FIG. 2 is a profile of the pattern, wherein the x and y axes represent the abscissa and ordinate, respectively, in units of: and (4) rice. The parameter equation of each section of the splicing curve is as follows:
first, a unit normal vector of the pattern profile directed inward can be calculated from equations (1) and (2). The minimum curvature radius rho in the three-section curve section of the pattern profile can be calculated by the formulas (3) to (5) and (8)min＝min{ρ(t)}|dir(t)＝1＝0.035m。
Next, the acceleration a of the machine tool is set to 9.8m/s2The error of the track chord height is 2.5 mu m, and the scanning speed is v0The maximum pattern outer region width under the constraint of the machine tool dynamic performance is calculated by the formula (14) as d when the maximum pattern outer region width is 1.7m/minN1.4476 mm. Setting a sweeping line spacing dcirOuter region width d matching the loop scan distance calculated by equation (16) of 50 μmN' -1.4 mm. Inner and outer boundary lines C generated by equation (16) using MATLAB softwared(t) referring to FIG. 3, the procedure described by the formulae (17) to (24) is applied to Cd(t) results after the selfing treatment are shown in FIG. 4. By means of FIG. 3Comparing the inner and outer dividing boundary lines of the pattern subjected to the selfing treatment with the inner and outer dividing boundary lines of the pattern subjected to the selfing treatment in the attached figure 4, it can be seen that the selfing of the inner and outer dividing boundary lines is better removed.
Then, the curve equation of each loop-scanning trajectory of the pattern outer region is calculated by the equation (25), and the MATLAB software is used to generate the loop-scanning trajectory of the pattern outer region without selfing treatment, which is shown in FIG. 5. The results of the generation of the scanning trajectory of the out-of-pattern region after the self-cross treatment according to the processes described in equations (17) to (24) are shown in fig. 6. As can be seen from the comparison between the figure 5 and the figure 6, the generation of the circular scanning track of the pattern outer area without selfing treatment has the advantages that the circular scanning track generated by the contour of the equidistant offset pattern is selfed and is seriously overlapped locally, and the tracks are not overlapped after selfing treatment, so that local overburning in actual laser processing can be avoided.
Finally, the inner zone line sweep distance d is setlineTaking theta as 0 degree in the scanning direction as 50 mu m, and calculating the line spacing d of the fine-adjusted line scanning track by the formula (28)line' -50.1 μm. Calculating the linear equation of each scanning track in the pattern by the formula (29), and generating a linear set L ═ L of the covered inner region by MATLAB software1,L2,…,Lj,…,LrThe result of the process is shown in fig. 7, and the result of the sweep trace in the pattern with the extra segments removed according to the process from equation (30) to equation (34) is shown in fig. 8. Comparing the initial generation of the line scanning track covered by the pattern in fig. 7 with the generation of the line scanning track in the pattern with the removal of the redundant segments in fig. 8, it can be seen that the laser line scanning processing track can be flexibly generated according to the required scanning direction and the scanning area by controlling the boundary of the generation area of the line scanning track and the slope of the straight line corresponding to the track.
By giving basic laser processing scanning track parameters and machine tool characteristic parameters, the method can realize automatic type judgment, internal and external area division and generation of corresponding area scanning tracks on processing patterns in an MATLAB environment. Especially, when some process parameters are obtained by analytical calculation, numerical simulation, iterative solution and other modes under the environment of scientific computing software, theoretical and technical support is provided for generating a scanning track meeting the requirements of dynamic response capability and edge processing quality consistency of a machine tool, the method lays a foundation for integration of laser processing process parameter planning and scanning track generation, and plays an important guiding role in planning and flexibly generating a laser scanning path in actual engineering processing.
Claims (1)
1. A track generation method for processing surface layer patterns by adopting a laser double scanning strategy is characterized in that the method divides an outer area and an inner area of the patterns and respectively adopts scanning strategies of circular scanning and line scanning; firstly, calculating curvature radius, unit normal vector and geometric parameters of the concave-convex direction of each point of a pattern contour curve by the pattern contour curve, and determining the minimum curvature radius and the position of the pattern contour curve; secondly, determining the maximum outer area width limited by a pattern contour curve and the limit processing capacity of a machine tool, matching the outer area width by combining a scanning line spacing condition, dividing the pattern into an inner area and an outer area by using equidistant bias lines of the pattern contour, and performing selfing treatment on an inner and outer distinguishing boundary line for a complex pattern with a splicing curve profile; then, equidistantly biasing the pattern contour to generate an outer zone circular scanning track, and performing selfing removal treatment on the circular scanning track for the complex pattern with the contour being a splicing curve; finally, generating a series of linear sets which have the scanning line spacing and cover the inner area, and calculating and removing the part of the linear set outside the inner area to generate an inner area scanning track; the method comprises the following specific steps:
step 1, calculating curve-related geometric parameters from the pattern outline curve
For example, when the profile curve c (t) is given by the parametric equation (x ═ x (t), y ═ y (t), and z ═ 0), when moving in the clockwise direction along c (t), the unit tangent vector is:
additionally setting unit vector
Point to the inside of C (t)The unit normal vector of (a) is:
the first derivative, the second derivative and the curvature radius of C (t) are respectively:
the direction of the second derivative vector of a certain point on the curve is the same as the direction from the point to the center of the osculating circle, so that the concave-convex direction of the curve section of the neighborhood of the point is reflected; the second derivative vector of C (t) is calculated as follows:
then according to
And
establishing curve concave-convex direction judgment parameters according to the difference of the directions:
wherein dir (t) ═ 1 indicates that the point neighborhood curve segment is in a convex shape, if dir (t) ═ 1 indicates that the point neighborhood curve segment is in a concave shape, if dir (t) ═ 0 indicates that the point neighborhood curve segment is in a straight line segment; the minimum radius of curvature of C (t) is expressed as:
ρmin＝min{ρ(t)}＝min{min{ρ(t)}|dir(t)＝1，min{ρ(t)}|dir(t)＝-1} (8)
wherein min { ρ (t) } memorydir(t)＝1And min { ρ (t) } counting the cellsdir(t)＝-1C (t) minimum radius of curvature of the convex portion and the concave portion, respectively;
step 2, dividing the pattern into an inner region and an outer region
On the basis of calculating all the geometric parameters of C (t) in the step 1, carrying out equidistant bias on C (t) to obtain an equidistant bias line, namely an expression form of an inner and outer distinguishing boundary line of the pattern:
wherein d isNIs an equidistant bias line Cd(t), the offset distance, i.e., the outer region width of the pattern;
and CdThe radius of curvature of (t) is expressed as:
ρN(t)＝ρ(t)-dir(t)dN (10)
the above formula indicates that for the curve segment concave upward in C (t), Cd(t) the radius of curvature of the corresponding location becomes larger, and for the convex curve segment on C (t), Cd(t) the radius of curvature of the corresponding position becomes smaller;
when C (t) is a first-order continuous curve
If ρmin＝min{ρ(t)}|dir(t)＝-1That is, when the minimum curvature radius of C (t) is located at the concave part and C (t) has the convex curve section, the constraint of the dynamic performance of the machine tool is relatively easy to satisfy only by Cd(t) has a minimum radius of curvature of ρ or moreminThe accessibility of the scanning speed of the whole outer area can be ensured; the maximum outer region width is obtained from equations (8) and (10):
dN＝min{ρ(t)}|dir(t)＝1-ρmin (11)
if ρmin＝min{ρ(t)}|dir(t)＝1When the minimum curvature radius is positioned at the convex part, the limit machining capacity of the machine tool determined by machining parameters and machine tool parameters needs to be considered; for the linear interpolation motion, micro-line segments approach to curve segments, the scanning speed in each micro-line segment undergoes the processes of acceleration, uniform speed and deceleration, and the acceleration and the planned scanning speed of the machine tool are respectively expressed as a and v0Then the velocity increases from 0 to v0When in use, is v0A; the more the time proportion of the uniform motion is, the smaller the influence of the acceleration/deceleration stage on the whole processing quality is, the limit processing capacity of the machine tool is defined when the acceleration and deceleration motion distance accounts for the total motion distance 1/10, and the overburning influence generated in the acceleration/deceleration stage can be ignored; the minimum linear scan distance is then expressed as:
in actual processing, v is planned0The curvature constraint of the pattern contour curve needs to be met, and enough margin exists;
because the approximated curve segment with small arc length can be regarded as a circular arc shape, and the radius of the circular arc is rho, and the chord height error is epsilon, the chord length s needs to satisfy:
the maximum outer region width at this time obtained from equations (10) and (12) is:
the determined width of the pattern outer region only meets the requirement of the dynamic performance of the machine tool, and the matching with the scanning line spacing is not considered; recording the line sweeping distance of the outer region as dcirThe circular scanning track that can be accommodated by the outer zone is selected according to actual needsThe quantity is as follows:
wherein INT (-) is a floor function; the outer zone width and the inner and outer zone boundary line equations matched with the circular sweep distance are obtained by the equations (9) and (15):
② when C (t) is formed by splicing curve segments
For each curve segment forming C (t), calculating according to the formula (i) and taking the minimum d in all the curve segmentsNA value; in addition Cd(t) selfing also occurs at locations corresponding to the vicinity of the first-order discontinuity in C (t), to avoid Cd(t) selfing treatment is carried out on the partial closed loop under the influence of the partial closed loop; uniformly dispersing C (t) into n points and calculating according to the formula (9) to obtain CdDiscrete point set form of (t):
P＝{P1,P2,…,Pk,…,Pn},Pk＝(xk,yk) (17)
wherein x iskAnd ykAre respectively a point PkThe abscissa and ordinate of (a); thus Cd(t) is approximately represented by a set of micro-straight line segments, i.e., PP ═ P1P2,…,PkPk+1,…,Pn-1PnGet curve Cd(t) converting from the intersection point to the intersection point of the two straight line segments; for any line segment PkPk+1The linear equation is as follows:
then any point P in Pm＝(xm,ym) To line PkPk+1The distance of (a) is:
for the numerator of the right side partial expression of the middle number of the above expression, if the absolute value operation is not carried out, the positive and negative of the numerator represents PmRelative to the straight line PkPk+1The position of (2): 0 indicates a point on the straight line, and positive and negative respectively indicate points on different sides of the straight line; it is referred to as a characterization point PmTo the straight line segment PkPk+1The parameter of the relative position is denoted sgn (d)mk) If two intersected straight-line segments exist in the PP, two end points of one straight-line segment are distributed on different sides of the other straight-line segment, namely the product of relative position parameters from the two end points to the other straight-line segment is determined to be-1; on the contrary, only if the product of the relative position parameters from a certain two adjacent points to a certain straight line segment is-1, the two straight line segments determined by the product are possible to intersect; in order to establish the criterion of intersection of certain two straight line segments in PP, the following matrix is constructed:
wherein, the value of each element of M is one of {0,1, -1 }; straight line segment PmPm+1And straight line segment PkPk+1The essential conditions for the intersection are:
Mmkand MkmPositions in the square matrix M are symmetrical about a main diagonal, and a self-crossing discrimination matrix of the curve is constructed:
Inter＝M+MT+2A (22)
wherein A is a matrix in which all of the elements of (n-1) × (n-1) are 1; the element with the Inter median value of 0 is the serial number of the straight line segment where the intersection occurs, namely the position of the curve self-intersection point; suppose a straight line segment PmPm+1And straight line segment PkPk+1Crossing, where m < m +1 < k +1, and where selfing occurs in a local small region, the equation corresponding to the two lines can be derived from the intersection point Pmk＝(xmk,ymk) The coordinates of (a) are:
special cases are as follows: when x ism+1＝xmAt a time there is
When x isk+1＝xkAt a time there is
The curve point set after selfing and self-intersection point supplementation is as follows:
step 3, generating a circular scanning track of the pattern outer area
For the circular scanning track of the pattern outer region, the circular scanning track is obtained by equally offsetting the pattern outline curve C (t); when scanning from the outside to the inside of the pattern, the curve equation of the ith circular scanning track is as follows:
in addition, when c (t) is formed by splicing curve segments, the circular scanning track is also subjected to selfing, and since the scanning track subjected to selfing causes a part of the processing area to be irradiated with laser for multiple times, so that the processing quality is deteriorated, and even the scanning track profile is distorted, in this case, the circular scanning track needs to be subjected to selfing removal according to the processes of equations (15) to (23);
step 4, generating the scanning track of the region in the pattern
For generating an intra-region sweep trajectory in a scientific computing software environment, the basic idea is to first define the position of the peripheral sweep trajectory from the trajectory generation region, and then generate a series of sets of straight lines L ═ L { L that cover the trajectory generation region at the desired scan line spacing1,L2,…,Lj,…,LrFinally, rejecting the part of the straight line outside the track generation area;
to determine L1And LrWhen the scanning direction k is selected according to actual needsLAfter tan theta, theta is an included angle between the scanning direction and the positive direction of the x axis, and for any point P in the passing point set Pk＝(xk,yk) And the slope is kLHas the linear equation of y-yk＝kL(x-xk) The intercept of the horizontal axis is easily known as:
the point P where the intercept of the horizontal axis is minimized and maximized is selected and designated as Pq1＝(xq1,yq1) And Pq2＝(xq2,yq2) When there are a plurality of corresponding points, description Cd(t) a slope of kLThe straight line segment of (1) can be selected only by selecting a point satisfying the condition, and under special conditions, when theta is equal to 0 DEG, P isq1And Pq2Respectively taking Cd(t) the uppermost point and the lowermost point, and P when θ is 90 DEGq1And Pq2Respectively taking Cd(t) leftmost point and rightmost point; l is1And LrShould be respectively associated with Pq1And Pq2Keeping a certain distance to avoid the line scanning track length being 0 or the circular scanning track and the line scanning track being coincident, wherein the distance is taken as the line distance d required by the internal region line scanninglineThen, the number of sweeping tracks that the inner area can accommodate is:
and the fine-tuning back row sweeping track line spacing of the whole inner area with the uniformly distributed row sweeping tracks is as follows:
further, the set of straight lines L ═ L1,L2,…,Lj,…,LrThe jth line scanning track L in thejThe equation of the straight line of (1) is:
next deleting the portion of L outside the region within the pattern; for linear scanning only two end points of the scanning path need be determined, i.e. LjAnd Cd(t) an intersection point; to determine the intersection point, LjDispersed as uniform point set Qj＝{Q1Q,Q2Q,…,QuQ,…,QtQ},QuQ＝(xuQ,yuQ) The discrete points are ensured to cover the inner area of the pattern and at most one L exists between the two adjacent pointsjAnd Cd(t) intersection, then straight line segment set QQj＝{Q1QQ2Q,…,QuQQ(u+1)Q,…,Q(t-1)QQtQAny straight line segment Q inuQQ(u+1)QAll satisfy the equation of a straight line described by equation (29), so that LjAnd Cd(t) solving for the intersection points translates to QQjJudging the intersection of the straight line segment in the PP and solving the intersection point; is easy to know QjAny point QuQ＝(xuQ,yuQ) Straight line segment P to PPkPk+1And any point P in Pk＝(xk,yk) To QQjMiddle arbitrary straight line segment QuQQ(u+1)QThe distance of (a) is:
in the above formula duQ→kAnd dk→uQThe absolute value sign of (1) is judged to be positive or negative and respectively recorded as sgnuQ→kAnd sgnk→uQRepresenting the relative position relation of points and straight line segments; the following matrix was constructed:
then straight line segment QuQQ(u+1)QAnd straight line segment PkPk+1The necessary conditions for sufficient intersection are as follows:
structure QQjAnd the PP intersection discrimination matrix is as follows:
wherein A is a matrix in which all of the elements of (t-1) × (n-1) are 1; then Inter2The element with a median value of 0 indicates the number of the straight line segment where the intersection occurred, assuming Inter2When (u, k) is 0, a straight line segment Q is indicateduQQ(u+1)QAnd straight line segment PkPk+1Crossing, obtaining the intersection point Q by the equation of two straight linesuQ,k＝(xuQ,k,yuQ,k) Namely the coordinate of one knife position point of the line scanning track:
in which, when theta is equal to 90 degrees in special cases,
when x isk+1＝xkWhen is, QuQ,k＝(xm,yuQ+kL(xk-xuQ))；
Complete solution of LjAfter scanning the locus knife position on all the lines, Q is addedjReplacing the inner points with the required cutter location points, and sequencing according to the scanning direction; in addition, in order to reduce the total idle stroke, the sequence of the tool positions needs to be reversed for the odd or even numbered tracks in the line set L.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010743519.4A CN112008248B (en) | 2020-07-29 | 2020-07-29 | Method for generating surface pattern track by laser double scanning strategy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010743519.4A CN112008248B (en) | 2020-07-29 | 2020-07-29 | Method for generating surface pattern track by laser double scanning strategy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112008248A CN112008248A (en) | 2020-12-01 |
| CN112008248B true CN112008248B (en) | 2021-05-18 |
Family
ID=73498537
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010743519.4A Active CN112008248B (en) | 2020-07-29 | 2020-07-29 | Method for generating surface pattern track by laser double scanning strategy |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112008248B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113096147B (en) * | 2021-04-08 | 2022-07-29 | 中国人民解放军国防科技大学 | MATLAB-based automatic laser marking shadow generation method |
| CN114472924B (en) * | 2022-01-12 | 2022-10-11 | 南昌大学 | Laser path planning method, system, computer and readable storage medium |
| CN114985945B (en) * | 2022-05-19 | 2024-02-20 | 深圳市铭镭激光设备有限公司 | Pattern marking method |
| CN116551215B (en) * | 2023-07-06 | 2023-09-05 | 北京新科以仁科技发展有限公司 | Laser scanning control method, device, equipment and storage medium of laser |
| CN117655563B (en) * | 2024-01-31 | 2024-05-28 | 成都沃特塞恩电子技术有限公司 | Laser cutting path planning method and device, electronic equipment and storage medium |
| CN117976507B (en) * | 2024-04-01 | 2024-06-04 | 新美光(苏州)半导体科技有限公司 | Electrode plate and design processing method and processing equipment thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105158769A (en) * | 2015-07-29 | 2015-12-16 | 北京理工大学 | Double-linkage bionic eye laser scanning imaging system based on MOEMS device |
| CN105665704A (en) * | 2016-03-11 | 2016-06-15 | 上海拓宝机电科技有限公司 | Metal laser selective melting method |
| WO2020025771A1 (en) * | 2018-08-01 | 2020-02-06 | Sei S.P.A. | Laser finishing method and apparatus for providing a finishing pattern on a workpiece |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102450074B1 (en) * | 2017-07-18 | 2022-09-30 | 스미또모 덴꼬 쇼오께쯔 고오낑 가부시끼가이샤 | Sintered products and their laser marking methods |
-
2020
- 2020-07-29 CN CN202010743519.4A patent/CN112008248B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105158769A (en) * | 2015-07-29 | 2015-12-16 | 北京理工大学 | Double-linkage bionic eye laser scanning imaging system based on MOEMS device |
| CN105665704A (en) * | 2016-03-11 | 2016-06-15 | 上海拓宝机电科技有限公司 | Metal laser selective melting method |
| WO2020025771A1 (en) * | 2018-08-01 | 2020-02-06 | Sei S.P.A. | Laser finishing method and apparatus for providing a finishing pattern on a workpiece |
Non-Patent Citations (1)
| Title |
|---|
| 图形激光标刻中的分区遗传算法;肖进胜 等;《光电子·激光》;20170228;第28卷(第2期);第223-229页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112008248A (en) | 2020-12-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112008248B (en) | Method for generating surface pattern track by laser double scanning strategy | |
| CN108508846B (en) | Curved surface spraying track planning method | |
| WO2020125040A1 (en) | Method for designing topological shape of curved surface partition machining trajectory on basis of vector field | |
| Castagnetti et al. | The domain of admissible orientation concept: a new method for five-axis tool path optimisation | |
| CN109571473B (en) | Error-controllable small line segment trajectory fairing method | |
| Lauwers et al. | Optimal and collision free tool posture in five-axis machining through the tight integration of tool path generation and machine simulation | |
| US6311098B1 (en) | Method and apparatus for preparing data on tool moving path, and machining method and system | |
| US9770784B2 (en) | Laser machining device and method for machining a workpiece by using a laser machining device | |
| CN109947049B (en) | Tool attitude angle feasible region solving method based on swing error | |
| CN110032140B (en) | Spherical cutter shaft vector planning method in five-axis machining | |
| Anotaipaiboon et al. | Curvilinear space-filling curves for five-axis machining | |
| CN119131314B (en) | Method and system for generating curved surface machining path of ultra-precise diamond lathe | |
| Wen et al. | Uniform coverage tool path generation for robotic surface finishing of curved surfaces | |
| JP2007279937A (en) | Method for machining contour surface and solid by numerical control single cutting tool | |
| CN113333785A (en) | Non-circular section part circumferential partition area variable spindle rotating speed turning method | |
| CN107491034A (en) | A kind of optimal tool orientation method based on covariant field functional | |
| Ao et al. | A smooth tool path generation method for ultraprecision turning discontinuous multi-freeform-surfaces with high machining efficiency | |
| JP2025518426A (en) | Systems and methods for surface fitting, path planing, and surface treatment of objects - Patents.com | |
| CN112621771A (en) | Cold spraying robot track planning method based on geodesic line | |
| Chu et al. | Optimal tool path generation and cutter geometry design for five-axis CNC flank milling of spiral bevel gears | |
| Lu et al. | Tool-path planning method for kinematics optimization of blade machining on five-axis machine tool | |
| CN110126101B (en) | An off-axis multi-mirror imaging system processing method | |
| CN108873805B (en) | A tool path optimization method for microlens array in slow-tool servo turning | |
| Xu et al. | Global optimal trajectory planning of mobile robot grinding for high-speed railway body | |
| Yin | A partitioning grinding method for complex-shaped stone based on surface machining complexity |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |