Spiral composite path planning method for any wall thickness

Abstract

The invention discloses a spiral composite path planning method for any wall thickness, and relates to the technical field of additive manufacturing, and the method comprises the following steps: S1, inputting parameters related to stacking of a planar spiral and an ascending spiral; s2, determining the number of layers of rising spiral stacking through a height interval Zlimit and a layer thickness Thickness parameter, and when a layer serial number i is smaller than the number of layers, calculating two groups of spiral filling lines and performing conversion so as to generate a layer of spiral path; s3, calculating a group of spiral filling lines containing two layers with the interval of Thickness, and converting the spiral filling lines into a spiral line; and S4, the step S3 is repeated for each layer, and when the maximum layer number is reached, the spiral lines of all the layers are connected into a spiral composite path. Through the spiral composite path strategy, the single-channel limitation can be broken, the filling requirement can be met inwards, and the whole-process continuous trend can be continuously kept in the stacking direction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of additive manufacturing, in particular to a spiral composite path planning method for arbitrary wall thickness. BACKGROUND

[0002] Path planning is a key step to realize the AM process planning process, and continuous path can avoid defects caused by frequent start and stop of the printing head, however, the spiral accumulation strategy of global continuity can only be used for non-filled structure, and it has limitations for hollow parts with different thickness, therefore, the spiral composite path generated for the hollow part with self-defined thickness by combining the planar spiral filling and the rising spiral accumulation can be simply referred to as thick-wall spiral path.

[0003] When the additive manufacturing technology is used for structures with large wall thickness, the existing filling path strategy cannot maintain continuity throughout the process, and the spiral accumulation path that maintains continuity throughout the process cannot take into account the filling requirements. SUMMARY

[0004] The purpose of the present application is to provide a spiral composite path planning method for arbitrary wall thickness to solve the problems raised in the background.

[0005] To achieve the above purpose, the present application provides the following technical scheme: a spiral composite path planning method for arbitrary wall thickness, the method comprising the following steps:

[0006] S1, input the parameters related to planar spiral and rising spiral accumulation, including layer thickness Thickness, interval Gap, spiral direction IsClockwise, spiral rule IsInner2Outer, radius interval RLimit and height interval ZLimit;

[0007] S2, determine the number of layers of the rising spiral accumulation through the height interval Zlimit and the layer thickness Thickness, when the layer number i is less than the number of layers, calculate two groups of spiral filling lines and transform them to generate a layer of spiral path, until the calculation of each layer path is completed, wherein the even layer attribute of the spiral rule IsInner2Outer and the odd layer attribute of the spiral direction IsClockwise are taken inversely;

[0008] S3, calculate a group of spiral filling lines containing two layers with an interval of layer thickness Thickness, and convert them into a spiral line;

[0009] S4, repeat step S3 for each layer, when the maximum number of layers is reached, all layer spiral lines are connected to form a spiral composite path.

[0010] Preferably, the input parameters mainly include four parameters, the parameters related to the planar spiral are RLimit, IsInner2Outer and IsClockwise, RLimit represents the thickness interval of the planar spiral, IsInner2Outer represents the pattern of the planar spiral from inside to outside, and IsClockwise represents the pattern of the planar spiral clockwise, and the parameters related to the ascending spiral accumulation are Zlimit, Zlimit represents the height interval of the accumulation.

[0011] Preferably, in the step S2, the spiral filling line is transformed by a set of circle contours, the circle contour is composed of a circle center matrix and a radius, the circle center matrix determines the position of the circle and the direction of the circle interpolation, and the radius determines the size of the circle, and the difference between the radii of the set of concentric circles is the interval Gap.

[0012] Preferably, when the group sequence number i is less than or equal to 2, the i-th set of circle contours is calculated, the number of turns of the planar spiral is calculated according to the radius interval RLimit and the interval, and when the turn sequence number j is less than the number of turns, the radius of the j-th turn of the circle is accumulated starting from the minimum value of the radius interval Rlimit with the interval Gap as the rule, so as to obtain a set of circle contours.

[0013] Preferably, if the value of the spiral rule IsInner2Outer is True, the order of the elements in the circle contour list is from small circle to large circle, otherwise the list is processed in reverse order, then a spiral line is generated using the set of circles, the circle matrix Mat is moved by a layer thickness, and the cycle is entered again, until the group sequence number i is greater than 2, the flow ends and two spiral lines on the plane with the interval being the given layer thickness are output.

[0014] Preferably, the circle interpolation of the circle contour is according to the given point number n, the radian π is divided into the parameter theta, the sign of the parameter theta is reversed when the spiral direction IsClockwise is False, otherwise it is unchanged;

[0015] Then, the i-th point is calculated as follows to obtain the original coordinate value:

[0016]

[0017] Where (X, Y, Z) represents the original coordinate value, RLimit.max represents the maximum thickness interval of the planar spiral, sin and cos represent the sine function and the cosine function respectively, theta represents the parameter of the given point number n, which is divided into the radian π, and i represents the point sequence number;

[0018] Finally, the original coordinate value is calculated and multiplied by the circle matrix to be transformed into the specified position.

[0019] Preferably, two layers of spiral lines are converted into a spiral line representing the spiral path of the layer according to the flow of calculating spiral lines, a set of open or closed curves which are fitted by points and represented by PA and PB respectively, where the number of elements in the list is n, and the i-th point in the list PA is transformed into a path point according to the rule of displacement profile points.

[0020] Preferably, the conversion of curves on the same plane into spiral lines and the conversion of curves on different planes into spiral lines are both achieved by converting the layered profile into a spiral line by displacing the points on the profile.

[0021] Compared with the prior art, the present application has the beneficial effects that:

[0022] The present application proposes a new path strategy for additive manufacturing technology, aiming to use a full-continuous path to print a rotary body part with an arbitrary given wall thickness, and combines plane spiral filling and rising spiral accumulation strategies to generate a spiral composite path for a hollow part with a self-defined thickness. Through the spiral composite path strategy, not only can the single-channel limitation be broken to meet the filling demand from the inside, but also the full-continuous trend can be maintained in the accumulation direction. The new path planning strategy not only enables the printing path to maintain a full-continuous state, but also takes into account the filling demand of an arbitrary wall thickness. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The overall method schematic diagram provided for the embodiments of the present application is shown in the figure;

[0024] Figure 2 The schematic diagram of the input parameter rule provided for the embodiments of the present application is shown in the figure;

[0025] Figure 3 The flowchart of generating a thick-wall spiral path provided for the embodiments of the present application is shown in the figure;

[0026] Figure 4 The flowchart of calculating two sets of spiral filling provided for the embodiments of the present application is shown in the figure;

[0027] Figure 5 The flowchart of circle interpolation provided for the embodiments of the present application is shown in the figure;

[0028] Figure 6 The flowchart of calculating spiral lines provided for the embodiments of the present application is shown in the figure;

[0029] Figure 7 The schematic diagram of a set of circle profiles and two-layer spiral filling provided for the embodiments of the present application is shown in the figure;

[0030] Figure 8 The schematic diagram of a set of plane spiral lines provided for the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] See also Figures 1 to 8 The present invention provides a technical solution: a spiral composite path planning method for arbitrary wall thickness, comprising the following steps:

[0033] S1. Input parameters related to planar spiral and ascending spiral stacking, including layer thickness Thickness, interval Gap, spiral direction IsClockwise, spiral rule IsInner2Outer, radius range RLimit and height range ZLimit;

[0034] S2. Determine the number of layers of the ascending spiral stacking by using the height interval Zlimit and layer thickness parameters. Although the spiral path maintains a continuous printing state throughout the entire process, it is calculated in layer order before becoming the final path. When the layer number i is less than the number of layers, two sets of spiral fill lines are calculated and transformed to generate a layer of spiral path until the calculation of each layer is completed. Among them, the even-numbered layer attribute of the spiral rule IsInner2Outer and the odd-numbered layer attribute of the spiral direction IsClockwise are respectively inverted, so that the style of the next layer of spiral path continues the trend of the current layer.

[0035] S3, calculating a set of spiral filling lines including two layers with a spacing of layer thickness Thickness, thereby converting the set into a spiral line;

[0036] S4, repeat step S3 for each layer. When the maximum number of layers is reached, all the spiral lines of the layers are connected to form a spiral composite path;

[0037] The input parameters mainly include four parameters. The parameters related to the planar spiral are RLimit, IsInner2Outer and IsClockwise. RLimit represents the thickness range of the planar spiral, IsInner2Outer represents the planar spiral from the inside to the outside, and IsClockwise represents the planar spiral in a clockwise style. The parameter related to the ascending spiral stacking is Zlimit, which represents the stacking height range.

[0038] In step S2, the helical filling line is transformed from a set of circle profiles, which are composed of a circle center matrix and a radius, the circle center matrix determines the position of the circle and the direction of the circle interpolation, and the radius determines the size of the circle, and the difference between the radii of the set of concentric circles is the interval Gap;

[0039] When the group number i is less than or equal to 2, the i-th set of circle profiles is calculated, and the number of turns of the planar helix is calculated according to the radius interval Rlimit and the interval, and when the turn number j is less than the number of turns, the radius of the j-th turn of the circle is accumulated starting from the minimum value of the radius interval Rlimit with the interval Gap as the rule, so as to obtain a set of circle profiles;

[0040] If the value of the helix rule IsInner2Outer is True, the order of the elements in the circle profile list is from small to large, otherwise the list is reversed, then a helix line is generated using the set of circles, the circle matrix Mat is moved by a layer thickness in height, and the loop is entered again until the group number i is greater than 2, the flow ends and outputs two helix lines on the interval of the given layer thickness;

[0041] The circle interpolation of the circle profile is based on the given point number n, which is divided into radians π as the parameter theta, and the sign of the parameter theta is reversed when the helix direction IsClockwise is False, otherwise it remains unchanged;

[0042] Then, the i-th point is calculated as follows to obtain the original coordinate value:

[0043]

[0044] Where (X, Y, Z) represents the original coordinate value, RLimit.max represents the maximum thickness interval of the planar helix, sin and cos represent the sine and cosine functions respectively, theta represents the parameter of the given point number n divided into radians π, and i represents the point number;

[0045] Finally, the original coordinate value is calculated and multiplied by the circle matrix to transform it to the specified position;

[0046] Two layers of helix lines are converted into a helix line representing the layer helix path according to the flow of calculating the helix line, a set of open or closed curves, which are fitted by points and represented by PA and PB respectively, the number of elements in which is n, and the i-th point in the list PA is transformed into a path point according to the rule of displacing the profile point;

[0047] The conversion of curves on the same plane to helix lines and the conversion of curves on different planes to helix lines are both through the displacement of the points on the profile to the layered profile to the helix line.

[0048] It is to be understood that the terminology used herein such as first and second, and the like, is only used to distinguish one entity or action from another entity or action, and does not necessarily require or imply any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0049] While embodiments of the present application have been shown and described with reference to particular embodiments thereof, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the spirit and scope of the application. The scope of the application is defined by the appended claims and their equivalents.

Claims

1. A spiral composite path planning method for arbitrary wall thickness, characterized in that: The method comprises the following steps: S1. Input parameters related to planar spiral and ascending spiral stacking, including layer thickness Thickness, interval Gap, spiral direction IsClockwise, spiral rule IsInner2Outer, radius range RLimit and height range ZLimit; S2. Determine the number of layers of the ascending spiral stacking by using the height interval Zlimit and the layer thickness parameter Thickness. When the layer number i is less than the number of layers, calculate two sets of spiral filling lines and transform them to generate a layer of spiral path until the calculation of each layer path is completed. In this case, the even-numbered layer attribute of the spiral rule IsInner2Outer and the odd-numbered layer attribute of the spiral direction IsClockwise are respectively inverted; S3, calculating a set of spiral filling lines including two layers with a spacing of layer thickness Thickness, thereby converting the set into a spiral line; S4. Repeat step S3 for each layer. When the maximum number of layers is reached, the spiral lines of all layers are connected to form a spiral composite path.

2. The spiral composite path planning method for arbitrary wall thickness according to claim 1, characterized in that: The input parameters mainly include four parameters. The parameters related to the planar spiral are RLimit, IsInner2Outer and IsClockwise. RLimit represents the thickness range of the planar spiral, IsInner2Outer represents that the planar spiral is from the inside to the outside, and IsClockwise represents that the planar spiral is in a clockwise style. The parameter related to the ascending spiral stacking is Zlimit, which represents the height range of the stacking.

3. The spiral composite path planning method for arbitrary wall thickness according to claim 1, characterized in that: In step S2, the spiral filling line is transformed by a set of circle contours, and the circle contours are composed of a circle center matrix and a radius. The circle center matrix determines the position of the circle and the direction of the circle interpolation, and the radius determines the size of the circle. The difference between the radii of this set of concentric circles is the interval Gap.

4. The spiral composite path planning method for arbitrary wall thickness according to claim 3, characterized in that: When the group number i is less than or equal to 2, the calculation of the i-th group of circular contour sets begins, and the number of turns of the planar spiral is calculated according to the radius interval RLimit and the spacing. When the circle number j is less than the number of turns, accumulation is performed starting from the minimum value of the radius interval Rlimit and using the spacing Gap as a rule to obtain the radius of the j-th circle, thereby obtaining a group of circular contours.

5. The spiral composite path planning method for arbitrary wall thickness according to claim 4, characterized in that: If the value of the spiral rule IsInner2Outer is True, the order of the elements in the circle contour list is from small circles to large circles, otherwise the list is reversed, and then this group of circles is used to generate a spiral line. The circle matrix Mat is moved up by one layer thickness and the loop is entered again until the group number i is greater than 2. The process ends and outputs two spiral lines on the plane with a given layer thickness interval.

6. The spiral composite path planning method for arbitrary wall thickness according to claim 2, characterized in that: The circular interpolation of the circular contour is based on the given number of points n, which is divided into arcs π as the parameter theta. When the spiral direction IsClockwise is False, the sign of the parameter theta is reversed, otherwise it remains unchanged. Then, the original coordinate value of the i-th point is obtained by the following calculation: Where (X, Y, Z) represents the original coordinates, RLimit.max represents the maximum thickness interval of the planar spiral, sin and cos represent the sine and cosine functions respectively, theta represents the parameter that divides the given number of points n into radians π, and i represents the point number; Finally, the original coordinates are calculated and multiplied by the circle matrix to transform to the specified position.

7. The spiral composite path planning method for arbitrary wall thickness according to claim 1, characterized in that: The two layers of spiral lines are converted into a spiral line representing the spiral path of this layer according to the process of calculating spiral lines. A set of open or closed curves are fitted by points, and PA and PB represent the point coordinate lists of the curves respectively, where the number of elements is n. For the i-th point in the list PA, it is transformed into a path point according to the rules of the displacement contour points.

8. The spiral composite path planning method for arbitrary wall thickness according to claim 1, characterized in that: The conversion of curves on the same surface into helices and the conversion of curves on different surfaces into helices are both achieved by converting the layered contours into helices through the points on the displacement contours.

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