Blade root area five-axis numerical control machining interference-free smoothing tool path generation method

Abstract

The invention discloses a blade root area five-axis numerical control machining interference-free smoothing tool path generation method. The method comprises the following steps: firstly, importing a to-be-processed blade root curved surface model, setting a processing cutter, and approaching parameter information such as an error maximum allowable value, minimum iteration times and row spacing; planning a cutter contact point trajectory according to the row spacing, obtaining discrete cutter contact points for the cutter contact point trajectory by an isoparametric method, and calculating an initial cutter location point and a cutter axis vector of the cutter contact points; a C (Configuration) space and a cutter shaft space are established for each cutter contact, a detection area is determined by projecting the cutter attitude in the cutter shaft space in the line spacing direction, a calculation method for cutter attitude interference detection and interference correction is provided, and the non-interference cutter shaft space of all the cutter contacts is calculated; and iteratively searching non-interference cutter shaft spaces of the cutter contacts on the two sides with the minimum angle change to obtain the smoothing cutter paths of different initial cutter shafts, and comparing the angle variance values of the smoothing cutter paths to obtain the non-interference smoothing cutter path.

Description

Technical Field

[0001] The present invention belongs to the technical field of Computer Aided Manufacturing (CAM), and particularly relates to a method for generating a non-interfering and fairing tool path for five-axis numerical control machining in the root region of a blade. Background Art

[0002] As a key component of an aeroengine and a gas turbine, a blade is generally composed of free-form surfaces, and its machining accuracy directly affects the performance of the whole machine. The root, as the load-bearing area of the blade part, connects the main body of the blade and the bottom plate area of the blade. The complex surface transition in the root restricts the position of the machining tool, making it prone to global interference and collision, resulting in difficulties in generating the tool path for root machining.

[0003] The main process of generating a non-interfering and fairing tool path for the blade root is to first calculate the C-space and the tool axis space of the tool contact points, and then determine whether interference occurs based on the tool posture in the tool axis space and the distance of the detection area, and correct the interfering tool axis. Then, fairing processing is performed on the corrected non-interfering tool path, and all tool axis vectors in the tool axis space are iterated.

[0004] The invention patent with the Chinese patent application number 201010590177.3 discloses a geometric and mechanical integrated optimization information processing method for a non-interfering tool path of a complex surface, including the following steps: (1) Discretize the ball-end milling cutter into a depth element model, which contains a discrete cuboid element set with depth information; (2) Sample the two-dimensional image of the tool and the machine tool environment, and use the depth information to determine the interference situation between the two. If there is interference, correct the tool position; determine whether the tool intersects with the workpiece. If it does, execute step (3); if not, continue to execute step (2); (3) Analyze the contact area between the tool and the workpiece using the depth element model, and calculate the instantaneous cutting force of the ball-end milling cutter; (4) Based on multi-constraint cutting conditions, use the sequential quadratic programming method to optimize the feed rate for complex surface machining. Compared with the prior art, the present invention has the advantages of high calculation efficiency, simple programming, and being applicable to multi-axis numerical control machining tool path verification and parameter optimization.

[0005] The invention patent with Chinese patent application number 201780089091.2 discloses a tool path generation method and device. A machining point on multiple columns of tool paths is set as an object machining point, and machining points within a specified range centered on the object machining point are selected as concerned machining points. By averaging the tool postures of the selected concerned machining points, the tool posture of the object machining point is calculated. The data related to the tool posture of the object machining point is corrected by the calculated average tool posture. The shape data of the workpiece to be machined and the shape data of the ball nose end mill used are obtained. An interference check between the workpiece and the ball nose end mill is performed based on the corrected tool posture data. Without generating interference between the workpiece and the ball nose end mill, a new tool path is generated based on the data related to the corrected tool posture.

[0006] The invention patent with Chinese patent application number 202110569283.1 discloses a rapid interference detection method for five-axis machining tool paths of NURBS (Non-Uniform Rational B-Splines) surfaces. This method constructs NURBS surfaces and establishes the five-axis machining tool motion trajectories of NURBS surfaces based on the isoparametric method, and analyzes the differences in interference detection in different regions of NURBS surfaces. For all tool contact points, the interference of the tool side in five-axis machining of NURBS surfaces is detected by selecting the points prone to interference on the machined surface based on the division points of the tool axis detection line. For the tool contact points in the non-convex surface region of the NURBS surface, the interference of the tool bottom in five-axis machining of NURBS surfaces is judged by selecting the points prone to interference on the machined surface based on the division points of the tool bottom circle diameter line. Compared with the traditional method, the method described in the present invention is simple and effective, and is of great significance for improving the quality of five-axis machining of NURBS surfaces.

[0007] The aims of the above-mentioned invention patents are all to perform tool interference detection on the initial tool path, thereby improving the safety of the machining process and the service life of the machine tool and the tool. The invention patent with Chinese Patent Application No. 201010590177.3 discretizes the ball-end mill into a depth element model, uses depth information to judge the interference situation between the two, and thus analyzes the tool-workpiece contact area using the depth element model to calculate the instantaneous cutting force of the ball-end mill, with higher calculation efficiency and simpler programming. The invention patent with Chinese Patent Application No. 201780089091.2 sets a machining point on a multi-column tool path as the object, calculates the tool posture of the object machining point by calculating the tool posture at the selected machining point of concern, corrects the data related to the tool posture of the object machining point by the average tool posture, and generates a new tool path based on the data related to the corrected tool posture without interference between the workpiece and the ball-end mill. The invention patent with Chinese Patent Application No. 202110569283.1 establishes the tool motion trajectory for five-axis machining of NURBS surfaces based on the isoparametric method, and then performs the detection and judgment of the flank interference of the five-axis machining tool. Compared with the traditional method, the method described in the invention is simple and effective. The first invention patent establishes a ball-end mill machining model and judges interference through depth, but two-dimensional interference detection does not involve the correction of the interference tool axis. The second and third patents can only perform interference detection and correction on the tool trajectory, and do not involve the generation of a non-interfering fairing tool path in the blade root region. Summary of the Invention

[0008] The aim of the embodiment of the present invention is to provide a method for generating a non-interfering fairing tool path for five-axis numerical control machining in the blade root region, so as to improve the error accuracy and reduce the number of tool position points.

[0009] Specifically, the technical solution of the present invention is as follows:

[0010] A method for generating a non-interfering fairing tool path for five-axis numerical control machining in the blade root region includes the following steps:

[0011] Step 1: Import the blade surface model and set the machining parameters;

[0012] Step 2: Calculate the initial tool position points and tool axis vectors of the tool contact point trajectory line in the root region;

[0013] Step 3: Calculate the non-interfering tool axis space for each tool contact point;

[0014] Step 4: Generate a non-interfering fairing tool path in the root region.

[0015] Furthermore, the machining parameters in Step 1 include: setting the tool radius R, the tool length L T , the total number of tool path rows n, and the safety distance d s .

[0016] Further, the calculation of the initial tool point and tool axis vector of the tool contact point trajectory line in step 2 includes:

[0017] Step 2.1 Plan the tool contact point trajectory line according to the row spacing;

[0018] Step 2.2 Discretize the tool contact point trajectory line by the equal parameter method to obtain a set of tool contact points;

[0019] Step 2.3 Obtain the tool point and tool axis vector according to the tool contact point.

[0020] Further, the calculation of the interference-free tool axis space for each tool contact point in step 3 includes:

[0021] Step 3.1 Establish the C space and tool axis space of the tool contact point;

[0022] Step 3.2 Project the tool axis vector and calculate the interference detection area on the bottom plate;

[0023] Step 3.3 Interference detection between the bottom plate projection area and the tool axis vector;

[0024] Step 3.4 Perform interference correction and establish the interference-free tool axis space of the tool contact point.

[0025] Further, the obtaining of the variable-step spiral tool path includes:

[0026] Step 4.1 Iterate the interference-free tool axis space of the tool contact points on both sides with the minimum angle;

[0027] Step 4.2 Calculate the variance value of the smooth tool path angle change starting from different tool axes;

[0028] Step 4.3 Obtain the interference-free smooth tool path.

[0029] Further, the step 2.1 of planning the tool contact point trajectory line according to the row spacing includes:

[0030] Obtain the tool contact point trajectory line. Let u and v be the row spacing and feed direction of the leaf root surface S to be machined respectively. From equation (1), the parametric line S(u i ) can be obtained as the tool contact point trajectory line CC i , where n is the total number of tool path rows, u min and u max are the minimum and maximum values of the u parameter respectively;

[0031]

[0032] Further, the step 2.2 of discretizing the tool contact point trajectory line by the equal parameter method to obtain a set of tool contact points:

[0033] Let CC iThe upper v parameter range is [v min ,v max ], the jth knife contact The length of the curve at j , curvature k j , tangent vector j and normal vector n j It can be expressed and obtained by formula (2), where S u and S v is the tangent vector of the point on the surface in the parameter directions u and v. The discrete CC points are obtained by the equal parameter method, and CC is calculated by formula (3) i Any knife contact point on the table, where m is the discrete number of knife contacts, and all knife contacts can be obtained by analogy.

[0034]

[0035]

[0036] Furthermore, the step 2.3 of obtaining the tool position point and the tool axis vector according to the tool contact point includes:

[0037] The initial tool position and tool axis vector of any tool contact point in the blade root tool contact trajectory can be calculated by formula (4), where the rake angle α is the angle between the tool axis vector T and the surface normal vector, and θ is the rotation angle around the surface normal vector.

[0038]

[0039] Furthermore, the step 3.1 of establishing the C space and the tool axis space of the tool contact point includes:

[0040] like Figure 3 As shown in (a), C space is a two-dimensional plane space with the fore-tilt angle as the horizontal coordinate and the rotation angle as the vertical coordinate. The C space is discretized with the rotation angle Δθ and the fore-tilt angle Δα. Each point represents a combination of fore-tilt angle and rotation angle. A tool axis vector can be defined by equation (4). Based on the discrete points of C space, the following can be constructed: Figure 3 (b) shows the hemispherical tool axis three-dimensional space, with the center of the circle as the tool position point. The vector to the grid point on the sphere can be calculated by substituting the discrete point of the C space into equation (4).

[0041] The single-blade machining only considers the collision interference between the tool and the base plate when machining the blade root area. The inspection area corresponds to the rake angle interval [0°, 90°] in the C space.

[0042] Furthermore, the step 3.2 of projecting the tool axis vector and calculating the interference detection area on the base plate includes:

[0043] Knife contact The tool axis to be measured in the initial tool axis space T(α k, θ k ) as an example, calculate the tool axis T(α k , θ k ) in the area where interference may occur on the blade bottom plate. As Figure 4 shown, in order to improve the interference detection efficiency, project the tool in the feed direction Y L and calculate the projected area on the bottom plate as the interference detection area F.

[0044] First, obtain the parameter bounding box of the area F by equally spacing the u and v parameter lines, and then divide the projected area F by equal parameters. As Figure 5 shown, divide the projected area with Δu and Δv as the equal parameter intervals. The intersection of every 4 u and v equal parameter lines forms a parametric surface.

[0045] Furthermore, the interference detection between the bottom plate projected area and the tool axis vector in step 3.3 includes:[[]]

[0046] Taking the surface S m,n on the projected area F as an example, give the interference detection calculation process of the tool axis T(α k , θ k ). The essence of interference detection is to compare the minimum distance d m,n from the tool axis vector to the surface S min with the tool radius R. If d min < R, interference occurs; if d min > R, no interference occurs. The discrete surface set {S m,n} can be calculated by Equation (5), where m and n are the discrete numbers in the u and v parameter directions respectively. To improve the calculation efficiency, use the 4 parameter vertices of the surface S m,n to replace S m,n for distance calculation.

[0047] The detailed process of the interference detection calculation of the tool axis T(α k , θ k ) to be measured is as follows:[[]]

[0048] {S i,j} = {(u i , v j ), (u i , v j+1 ), (u i+1 , v j+1 ), (u i+1 , v j )}{i, j = 1, 2, 3.....n} (5)

[0049] Step 3.3.1 Calculate T(α k , θ k ) and the surface S m,nParameter vertex p 2 The distance d(p 2 )

[0050] like Figure 6 As shown, the surface S m,n The four parameter vertices are p 1 (u m ,v n ), p 2 (u m ,v n-1 ), p 3 (u m-1 ,v n-1 ), p 4 (u m-1 ,v n ). With parameter vertex p 2 (u m ,v n-1 ) as an example, calculate the tool axis and parameter vertex p respectively 1 、p 2 、p 3 、p 4 The distance between them. First connect the points p 2 (u m ,v n-1 ) and knife point Forming vectors The vector is calculated by formula (6): With the tool axis T(α k ,θ k ), and by substituting β into formula (7), we can calculate p 2 (u m ,v n-1 ) and the distance d(p 2 ). Similarly, calculate the tool axis and the remaining parameter vertex p 1 、p 3 、p 4 The distance between them, the minimum distance d is obtained by formula (8) min , as the tool axis T(α k ,θ k ) and surface S m,n distance.

[0051]

[0052] d min ={d(p 1 ),d(p 2 ),d(p 3 ),d(p 4 )}(8)

[0053] Step 3.3.2 Determine whether the tool axis T(α k , θ k ) interferes

[0054] For the distance d k , θ k ) between the tool axis T(α m,n and the surface S min , if d min > R, the non-interference condition is satisfied, and the tool axis vector T(α k , θ k ) does not interfere with the surface S m,n . Similarly, judge the next surface S m,n+1 until the tool axis vector T(α k , θ k ) has no interference with the surface set {S m,n}. If d min < R, it means that there is a parametric vertex that interferes with the tool axis vector T(α k , θ k ). Calculate the next tool axis vector T(α k+1 , θ k+1 ) according to Equation (9). Similarly, judge whether T(α k+1 , θ k+1 ) interferes until the tool contact point of all the tool axis vectors to be measured in the initial tool axis space is determined.

[0055] T(α k+1 , θ k+1 ) = T(α k + Δα, θ k + Δθ) (9)

[0056] Put the tool axis vectors to be measured at the tool contact point into the interference vector set and the non-interference vector set respectively. As Figure 7 shown, draw the non-interference tool axis space of the point .

[0057] Furthermore, the step 3.4 of interference correction and establishment of the non-interference tool axis space of the tool contact point includes:

[0058] Taking the interference vector T in the interference tool axis set at the tool contact point as an example, correct the interference vector T 0 . After correction, the tool axis vector T 0 satisfies the non-interference condition and is put into the non-interference vector set 1 . The detailed correction calculation process is as follows: The detailed correction calculation process is as follows:

[0059] Step 3.4.1 As shown in Figure 8 , T 0 is the interference cutter axis vector that needs to be corrected, and T 1 is the corrected non-interference cutter axis vector, where d min is the shortest distance from the surface S calculated in Step 3.3.1 m,n to the cutter axis, R is the cutter radius of the ball-end cutter, and the theoretical minimum correction distance Δd can be calculated from Equation (10) min . The vector and the cutter axis vector T 0 The included angle β is obtained from Equation (6), and the required theoretical minimum correction angle γ can be calculated from Equation (11). Jump to Step 3.4.2

[0060] Δd min = R - d(10)

[0061]

[0062] Step 3.4.2 Step 3.4.1 calculates the theoretical minimum correction angle γ for correcting from the interference cutter axis T 0 to T 1 . When d min = R, theoretically the cutter just touches the blade bottom plate, but the cutter axis T 1 cannot be directly used for actual machining. Manually increase the safety distance d s , and re-correct the position of the cutter axis vector T 1 . As shown in Figure 9 , the safety distance correction represents the process of correcting from the interfering cutter axis vector T 0 to the theoretically tangent cutter axis vector T 1 , and then from the tangent cutter axis vector T 1 to the safety cutter axis vector T 2 process, and the corresponding distance from the surface S m,n is corrected from d min to the distance R, and then corrected to the safety distance R + d s ; the corresponding angle is corrected from β to β + γ + δ, which can be calculated from Equation (12). The corrected cutter axis vector T 2 satisfies the non-interference condition at this point

[0063]

[0064] Step 3.4.3 Bring the cutter axis vector T 2 with safety distance correction back to Step 3.3 for re-interference detection. After determining that there is no interference, project the cutter axis T 2 with the rake angle and rotation angle to obtain the non-interference cutter axis space of the corrected point . As shown inFigure 7 As shown, taking any interference cutter axis vector as an example, after interference correction, the theoretical correction angle is γ, and a new cutter axis vector is obtained. After adding a safety distance, the correction angle changes to γ + δ, and the new cutter axis vector is

[0065] The calculation process of the interference-free cutter axis space of the tool contact point is as Figure 10 shown.

[0066] Furthermore, step 4 iterates the interference-free cutter axis space of the tool contact points on both sides with the minimum angle; calculates the variance value of the change in the fairing tool path angle starting from different cutter axes; and obtains the interference-free fairing tool path. It includes:

[0067] Step 4.1 As Figure 11 shown, the cutter axis vector represents all interference-free cutter axis vectors in the cutter axis space of the tool contact point Taking the starting cutter axis vector as an example and substituting it into Equation (4), the rake angle of the cutter axis is calculated as the starting rake angle of the fairing tool path.

[0068] Step 4.2 Search for the interference-free cutter axis vectors with the minimum change angle of the tool contact points and on both sides. Use step 3.3 to calculate the interference-free cutter axes and of the tool contact points and respectively. Calculate the corresponding inclination angles and using Equation (4). Then, calculate the inclination angle change values between the sets and and using Equation (13), and calculate the minimum change inclination angle Δα min . The angles min corresponding to the minimum Δα and are substituted into Equation (4) to calculate the cutter axis vectors of the tool contact points and put them into the tool path vector set with the starting cutter axis .

[0069]

[0070]

[0071] Step 4.3 Continue to iterate on both sides. If the tool contact point Exactly at the midpoint of the i-th tool path row, repeating steps 4.1 and 4.2 can calculate the fairing tool path vector of the i-th row. Jump to step 4.5, otherwise go to step 4.4.

[0072] Step 4.4 If the tool contact point is not the midpoint of the i-th tool path row. Repeat steps 4.1 to 4.3, and finally there will be remaining unilateral tool contact points. Taking the fairing optimization of the tool axis vectors of the left tool contact points as an example, after bilateral iteration, only the tool contact point remains in the i-th tool path row. Without fairing processing, calculate the unilateral fairing tool axis vector from equations (15) and (16), and the minimum Δα min angle and are substituted into equation (4) to calculate the tool axis vector of the tool contact point and put it into the fairing vector set Similarly, obtain the complete fairing optimized tool path vector of the i-th row

[0073]

[0074] Step 4.5 Steps 4.1 to 4.4 have calculated the fairing tool path tool vectors starting with as the starting tool axis Similarly, calculate the fairing tool path tool vectors starting with as the starting tool axis

[0075] Step 4.6 Substitute all the fairing tool paths of the i-th row into equation (17) respectively to calculate the angular variance values of each fairing tool path and put them into the variance set {ν k}. Among them is the angle corresponding to the starting tool axis vector of different fairing tool paths.

[0076]

[0077] To reduce the vibration of the machine tool during processing and extend the service life of the tool, select the fairing tool path with the minimum variance k in the variance set {ν } as the processing tool path, which can be obtained by calculation from (18).

[0078]

[0079] The detailed tool path fairing processing flow is as Figure 12 shown.

[0080] The implementation of the present invention also provides a terminal, including:

[0081] at least one processor; and,

[0082] a memory communicatively connected to the at least one processor; wherein,

[0083] the memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor is enabled to execute the method for generating a collision-free fairing tool path for five-axis numerical control machining of a blade root region as described in any one of claims 1 to 13.

[0084] An embodiment of the present invention further provides a computer-readable storage medium storing a computer program, characterized in that when the computer program is executed by a processor, the method for generating a collision-free fairing tool path for five-axis numerical control machining of a blade root region as described in any one of claims 1 to 13 is implemented.

[0085] The present invention discloses a method for generating a collision-free fairing tool path for five-axis numerical control machining of a blade root region. The tool contact point trajectory line is planned according to the row spacing, discrete tool contact points are obtained by the equal parameter method for the tool contact point trajectory line, and the initial tool position points and tool axis vectors of the tool contact points are calculated; a C space and a tool axis space are established for each tool contact point, the detection area is determined by projecting the tool posture in the tool axis space onto the row spacing direction, a calculation method for tool posture interference detection and interference correction is proposed, and the collision-free tool axis space of all tool contact points is calculated; the collision-free tool axis space of the tool contact points on both sides is iteratively searched with the minimum angle change to obtain fairing tool paths with different starting tool axes, and by comparing the angle variance values of each fairing tool path, a collision-free fairing tool path is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplary illustrations do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, unless otherwise stated, and the drawings in the drawings do not constitute a scale limitation.

[0087] Figure 1 is a schematic flow chart of a method for generating a collision-free fairing tool path for five-axis numerical control machining of a blade root region according to an embodiment of the present invention;

[0088] Figure 2 is a schematic diagram of tool position points and tool axis vectors according to an embodiment of the present invention;

[0089] Figure 3 is the tool contact point C space and tool axis space according to an embodiment of the present invention;

[0090] Figure 4 is a schematic diagram of the projection of the tool posture on the bottom plate according to an embodiment of the present invention;

[0091] Figure 5 is a schematic diagram of isoparametric division of a projection area according to one embodiment of the present invention;

[0092] Figure 6 is a schematic diagram of the interference distance of the cutter axis vector according to one embodiment of the present invention;

[0093] Figure 7 is a schematic diagram of the interference-free cutter axis space of the cutter contact point according to one embodiment of the present invention;

[0094] Figure 8 is a schematic diagram of the theoretical interference correction angle according to one embodiment of the present invention;

[0095] Figure 9 is a schematic diagram of the safety distance correction according to one embodiment of the present invention;

[0096] Figure 10 is a flow chart of calculating the interference-free cutter axis vector space according to one embodiment of the present invention;

[0097] Figure 11 is a schematic diagram of bilateral iterative search for a fairing cutter axis according to one embodiment of the present invention;

[0098] Figure 12 is a schematic diagram of fairing cutter path processing according to one embodiment of the present invention;

[0099] Figure 13 is a schematic diagram of an overall blade model according to one embodiment of the present invention;

[0100] Figure 14 is a schematic diagram of a blade root clearing cutter path according to one embodiment of the present invention;

[0101] Figure 15 is a schematic diagram of blade machining simulation according to one embodiment of the present invention. Detailed implementation manners

[0102] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the following will elaborate on each implementation manner of the present invention with reference to the accompanying drawings. However, those of ordinary skill in the art can understand that in each implementation manner of the present invention, many technical details are provided for the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following implementation manners, the technical solutions claimed in the present application can still be achieved. The division of the following embodiments is for convenience of description and should not constitute any limitation on the specific implementation manner of the present invention. The various embodiments can be combined and cross-referenced with each other on the premise of no contradiction.

[0103] The present invention proposes a variable-step spiral tool path generation method for five-axis machining of a blade curved surface circular cutter. Refer to Figure 1 , which includes the following specific steps:

[0104] Step 1: Import the surface model and set the tool radius R, fillet radius r, tool length L T , the total number of tool path rows n, and the safety distance d s .

[0105] Step 2: Calculate the initial tool position points and tool axis vectors of the tool contact point trajectory line in the root region of the blade;

[0106] Step 2.1: Obtain the tool contact point trajectory line. Let u and v be the row spacing and feed direction of the parameter root surface S to be machined respectively. The parameter line S(u i ) can be obtained as the tool contact point trajectory line CC i , where n is the total number of tool path rows, u min and u max are the minimum and maximum values of the u parameter respectively;

[0107]

[0108] Step 2.2: Calculate the discrete tool contact points on the tool contact point trajectory line. Let the v parameter range on CC i be [v min , v max . The curve length L , curvature k j , tangent vector t j and normal vector n j at the jth tool contact point j can be expressed and obtained by Equation (2), where S u and S v are the tangent vectors of the points on the surface in the parameter directions u and v.

[0109] Obtain the discrete CC points by the equal-parameter method, and calculate any tool contact point on CC i by Equation (3), where n is the number of discrete tool contact points, and so on to find all tool contact points.

[0110]

[0111]

[0112] Step 2.3: Obtain the initial tool position points and tool axis vectors of the tool contact points. The initial tool position points and tool axis vectors of any tool contact point in the root tool contact point trajectory line can be obtained by Equation (4), where the rake angle α is the angle between the tool axis vector T and the surface normal vector, and θ is the rotation angle around the surface normal vector.

[0113]

[0114] The initial tool position points and tool axis vectors of all tool contact points in the spiral tool path can be obtained through iterative steps 2.1 to 2.3.

[0115] Step 3 calculates the interference-free tool axis space for each tool contact point. Take the set of tool contact points in the i-th row of the root blade tool path as an example to describe the calculation process.

[0116] Step 3.1 Establish the C-space and tool axis space of the tool contact point

[0117] As Figure 3 (a) shows, the C-space is a two-dimensional plane space with the rake angle as the abscissa and the rotation angle as the ordinate. Discretize the C-space with the rotation angle Δθ and the rake angle Δα. Each point represents a combination of rake angle and rotation angle, and a tool axis vector can be defined by Equation (4). According to the discrete points in the C-space, a hemispherical tool axis three-dimensional space as shown in Figure 3 (b) can be constructed. The center of the sphere is the tool position point, and the vector from the center of the sphere to the grid points on the spherical surface can be calculated by substituting the discrete points in the C-space into Equation (4).

[0118] When machining a single blade and only considering the collision interference between the tool and the bottom plate in the root blade machining area, the inspection area corresponds to the rake angle interval [0°, 90°] in the C-space.

[0119] Step 3.2 Project the tool axis vector and calculate the interference detection area on the bottom plate

[0120] Take the tool contact point as an example. In the initial tool axis space, for the tool axis T(α k , θ k ), calculate the area where the tool axis T(α k , θ k ) may interfere with the blade bottom plate. As Figure 4 shows, to improve the interference detection efficiency, project the tool along the feed direction Y L and calculate the projected area on the bottom plate as the interference detection area F.

[0121] First, obtain the parameter bounding box of area F by equally spacing the u and v parametric lines, and then equally divide the projected area F using the same parameters. As Figure 5 shows, divide the projected area with Δu and Δv as the equal parameter intervals. The intersection of every 4 u and v equal parameter lines forms a parametric surface.

[0122] Step 3.3 Interference detection between the bottom plate projected area and the tool axis vector

[0123] Take the surface S m,n on the projected area F as an example. For the tool axis T(α k ​, θ k ) interference detection calculation process. The essence of interference detection is to compare the minimum distance d from the tool axis vector to the surface S m,n with the tool radius R. If d min < R, interference occurs. If d min > R, no interference occurs. The discrete surface set {S min} can be calculated from Equation (5), where m and n are the discrete numbers in the parameter u and v directions respectively. To improve the calculation efficiency, the 4 parameter vertices of the surface S m,n are used to replace S m,n for distance calculation. m,n

[0124] The detailed process of interference detection calculation for the tool axis T(α k , θ k ) is as follows:

[0125] {S i,j} = {(u i , v j ), (u i , v j+1 ), (u i+1 , v j+1 ), (u i+1 , v j )}{i, j = 1, 2, 3.....n} (5)

[0126] Step 3.3.1 Calculate the distance d(p k , θ k ) between T(α m,n ) and the parameter vertex p 2 of the surface S 2

[0127] As Figure 6 shown, the 4 parameter vertices of the surface S m,n are respectively p 1 (u m , v n ), p 2 (u m , v n-1 ), p 3 (u m-1 , v n-1 ), p 4 (u m-1 , v n ). Taking the parameter vertex p 2 (u m , v n-1 ) as an example, calculate the distances between the tool axis and the parameter vertices p 1 , p 2 , p 3 , p4 The distance between. First, connect point p 2 (u m , v n-1 ) and the tool point to form a vector Calculate the vector by Equation (6) and the included angle β between the vector and the tool axis T(α k , θ k ). Substitute β into Equation (7) to calculate the distance d(p 2 (u m , v n-1 ) between the tool axis. Similarly, calculate the distances between the tool axis and the remaining parameter vertices p 2 ), p 1 , p 3 , p 4 . Obtain the minimum distance d min by Equation (8), which is used as the distance between the tool axis T(α k , θ k ) and the surface S m,n .

[0128]

[0129] d min = {d(p 1 ), d(p 2 ), d(p 3 ), d(p 4 )}(8)

[0130] Step 3.3.2 Determine whether the tool axis T(α k , θ k ) interferes

[0131] For the distance d k between the tool axis T(α k , θ m,n ) and the surface S min , if d min > R, satisfying the non - interference condition, the tool axis vector T(α k , θ k ) does not interfere with the surface S m,n . Similarly, judge the next surface S m,n+1 until the tool axis vector T(α k , θ k ) has no interference with the surface set {S m,n}. If d min < R, it means that there is a parameter vertex that interferes with the tool axis vector T(α k , θ k ). Calculate the next tool axis vector T(α by Equation (9)k+1 , θ k+1 ), similarly, judge T(α k+1 , θ k+1 ) to check if interference occurs until the tool contact point is determined All the tool axis vectors to be measured in the initial tool axis space.

[0132] T(α k+1 , θ k+1 ) = T(α k + Δα, θ k + Δθ)(9)

[0133] Put the tool axis vectors to be measured of the tool contact point into the interference vector set and the non - interference vector set As shown in Figure 7 , draw the non - interference tool axis space of the point .

[0134] Step 3.4 Interference correction and establish the non - interference tool axis space of the tool contact point

[0135] Take the interference vector T in the interference tool axis set of the tool contact point as an example, correct the interference vector T 0 . After correction, the tool axis vector T 0 meets the non - interference condition and is put into the non - interference vector set 1 . The detailed correction calculation process is as follows:

[0136] Figure 8 Step 3.4.1 As shown in Figure 8 , T 0 is the interference tool axis vector to be corrected, and T 1 is the non - interference tool axis vector after correction, where d min is the shortest distance from the surface S m,n calculated in Step 3.3.1 to the tool axis, and R is the tool radius of the ball - end mill. The theoretical minimum correction distance Δd min can be calculated from Equation (10). The angle β between the vector and the tool axis vector T 0 is obtained from Equation (6), and the theoretical minimum correction angle γ required can be calculated from Equation (11). Jump to Step 3.4.2.

[0137] Δd min = R - d(10)

[0138]

[0139] Step 3.4.2 In Step 3.4.1, calculate the distance from the interference tool axis T 0Corrected to T 1 The theoretical minimum correction angle γ. When d min = R, theoretically the cutting tool is exactly tangent to the blade bottom plate, but the tool axis T 1 cannot be directly used for actual machining. Manually increase the safety distance d s , and re-correct the position of the tool axis vector T 1 . As Figure 9 shown, the safety distance correction means correcting from the interfering tool axis vector T 0 to the theoretically tangent tool axis vector T 1 , and then correcting from the tangent tool axis vector T 1 to the safe tool axis vector T 2 process. Correspondingly, the distance from the surface S m,n is corrected from d min to the distance R, and then corrected to the safety distance R + d s ; the corresponding angle is corrected from β to β + γ + δ, which can be calculated from Equation (12). The corrected tool axis vector T 2 satisfies the non-interference condition at this point.

[0140]

[0141] Step 3.4.3 Bring the tool axis vector T 2 with safety distance correction back to Step 3.3 to re-perform interference detection. After determining that there is no interference, project the tool axis T 2 with the rake angle and rotation angle to obtain the non-interference tool axis space of the corrected point . As Figure 7 shown, taking any interfering tool axis vector as an example, after interference correction, the theoretical correction angle is γ, and a new tool axis vector is obtained. After adding the safety distance, the correction angle changes to γ + δ, and the new tool axis vector is

[0142] The calculation process of the non-interference tool axis space of the tool contact point is as Figure 10 shown.

[0143] Step 4 Generate a non-interference fairing tool path for the root region of the blade

[0144] Step 4.1 As Figure 11 shown, the tool axis vector represents all non-interference tool axis vectors in the tool axis space of the tool contact point . Taking the starting tool axis vector as an example, substitute it into Equation (4) to calculate the rake angle of the tool axis as the starting rake angle of the fairing tool path.

[0145] Step 4.2 Search for cutter contact points on both sides and the interference-free cutter axis vectors with the minimum change angle. Calculate the interference-free cutter axes of the cutter contact points and respectively using Step 3.3 and Calculate the corresponding inclination angles and using Equation (4), and then calculate the inclination angle change values between the sets and and respectively using Equation (13). Calculate the minimum change in inclination angle Δα using Equation (14) min , and obtain the angles min corresponding to the minimum Δα and Substitute them into Equation (4) to calculate the cutter axis vectors of the cutter contact points and put them into the cutter path vector set with the starting cutter axis being .

[0146]

[0147] Step 4.3 Continue to iterate on both sides. If the cutter contact point exactly lies at the midpoint of the i-th row of cutter paths, repeat Steps 4.1 and 4.2 to calculate the fairing cutter path vectors of the i-th row Jump to Step 4.5; otherwise, go to Step 4.4

[0148] Step 4.4 If the cutter contact point is not the midpoint of the i-th row of cutter paths. Repeat Steps 1 to 3, and eventually there will be remaining single-sided cutter contact points. Taking the fairing optimization of the cutter axis vectors of the left cutter contact points of the cutter contact point as an example, after bilateral iteration, only the cutter contact point in the i-th row of cutter paths remains un-faired. Calculate the single-sided fairing cutter axis vectors using Equations (15) and (16), and obtain the angles min corresponding to the minimum Δα and Substitute them into Equation (4) to calculate the cutter axis vector of the cutter contact point and put it into the fairing vector set Similarly, obtain the complete fairing optimized cutter path vectors of the i-th row

[0149]

[0150] Step 4.5 Steps 4.1 to 4.4 have calculated the fairing cutter path cutter vectors starting from as the starting cutter axis​ Similarly, calculate respectively the smooth tool path tool vectors starting from

[0151] Step 4.6 Substitute all the smooth tool paths of the i-th row into Equation (17) respectively, calculate the angular variance values of each smooth tool path, and put them into the variance set {ν k}. Among them is the corresponding angle of the starting tool axis vector of different smooth tool paths.

[0152]

[0153] To reduce the vibration of the machine tool during processing and extend the service life of the tool, select the smooth tool path with the minimum variance k in the variance set {ν } as the processing tool path, which can be obtained by calculation from (18).

[0154]

[0155] The detailed tool path smoothing process is as Figure 12 shown.

[0156] An embodiment of the present invention also provides a terminal, including:

[0157] at least one processor; and,

[0158] a memory communicatively connected to the at least one processor; wherein,

[0159] the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the equal-error tool path generation method for five-axis machining of a parameter surface flat-bottom cutter proposed by the present invention.

[0160] Among them, the memory and the processor are connected by a bus. The bus can include any number of interconnected buses and bridges. The bus connects various circuits of one or more processors and memories together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits together, which are well known in the art. Therefore, they will not be further described herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be an element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on the transmission medium. The data processed by the processor is transmitted on the wireless medium through the antenna. Further, the antenna also receives data and transmits the data to the processor.

[0161] The processor is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. The memory can be used to store the data used by the processor when executing operations.

[0162] Embodiments of the present invention also provide a computer-readable storage medium storing a computer program, which when executed by a processor implements the method for generating an equal-error tool path for five-axis machining of a parametric surface end mill proposed by the present invention. Storing a computer program. When the computer program is executed by a processor, the above method embodiments are implemented.

[0163] That is, those skilled in the art can understand that all or part of the steps in implementing the methods of the above embodiments can be completed by instructing relevant hardware through a program. The program is stored in a storage medium, including several instructions for causing a device (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage media include: USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks, etc., which can store program codes.

[0164] A typical embodiment of the present invention is as follows:

[0165] Select Figure 13 A typical blade surface in [the relevant content] is taken as an example. The tool is a ball nose end mill with a diameter of 3 mm and a length of 50 mm. The total number of tool path rows at the blade root is 30, and the number of tool position points in each row is 120. Table 1 shows the blade model parameters and machining tool parameters. Figure 14 FIG. [figure number] is a schematic diagram of the tool axis corresponding to the interference-free fairing tool path in the blade root region and the interference-free fairing tool path in the blade root region. Figure 15 FIG. [figure number] is a simulation diagram of the blade after generating the interference-free fairing tool path, verifying the feasibility of the present invention.

[0166] Table 1 Parameter information of the blade model and the machining tool

[0167]

[0168] In summary, the present invention provides a method for generating a collision-free smooth tool path for five-axis numerical control machining of the blade root region. The tool contact point trajectory line is planned according to the row spacing, discrete tool contact points are obtained by the equal parameter method for the tool contact point trajectory line, and the initial tool position points and tool axis vectors of the tool contact points are calculated. C space and tool axis space are established for each tool contact point. By projecting the tool posture in the tool axis space onto the row spacing direction, the detection area is determined, and a calculation method for tool posture interference detection and interference correction is proposed to calculate the collision-free tool axis space of all tool contact points. The collision-free tool axis space of the tool contact points on both sides is iteratively searched with the minimum angle change to obtain smooth tool paths with different starting tool axes. By comparing the angle variance values of each smooth tool path, the collision-free smooth tool path is obtained.

[0169] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present invention, and in practical applications, various changes can be made in form and details without departing from the spirit and scope of the present invention.

Claims

1. A method for generating interference-free smooth tool paths for five-axis CNC machining of blade root areas, characterized in that: The following steps are involved: Step 1: Import the blade surface model and set the processing parameters; Step 2: Calculate the initial tool position point and tool axis vector of the tool contact point trajectory in the blade root area; Step 3 calculates the interference-free tool axis space of each tool contact point; Step 4 generates a non-interference smooth tool path in the blade root area.

2. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 1 is characterized in that: The processing parameters include: setting the tool radius R, tool length L T , total number of tool paths n, safety distance d s .

3. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 1 is characterized in that: The step 2 of calculating the initial tool position point and tool axis vector of the tool contact point trajectory line in the blade root area includes: Step 2.1 Plan the tool contact point trajectory according to the line spacing; Step 2.2 discretize the knife contact point trajectory using the equal parameter method to obtain the knife contact point set; Step 2.3 obtains the tool position point and tool axis vector according to the tool contact point.

4. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 1 is characterized in that: The step 3 of calculating the interference-free tool axis space of each tool contact point includes: Step 3.1 Establish the C space and tool axis space of the tool contact point; Step 3.2 Project the tool axis vector and calculate the interference detection area on the base plate; Step 3.3: Interference detection between the projection area of ​​the base plate and the tool axis vector; Step 3.4 corrects the interference and establishes the interference-free tool axis space of the tool contact point.

5. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 1 is characterized in that: The acquisition step 4 generates a non-interference smoothing tool path in the blade root area, including: Step 4.1 Iterate the non-interference tool axis space of the tool contact points on both sides at the minimum angle; Step 4.2 calculates the variance of the smoothing tool path angle change starting from different tool axes; Step 4.3 obtains the interference-free smooth tool path.

6. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 3 is characterized in that: The step 2.1 of planning the contact point trajectory according to the line spacing includes: Obtain the tool contact point trajectory line, let u and v be the line spacing and feed direction of the blade root surface S to be processed, respectively. The parameter line S(u i ) as the knife contact trajectory CC i , where n is the total number of toolpath rows, u min and u max are the minimum and maximum values ​​of the u parameter respectively.

7. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 3 is characterized in that: The step 2.2 uses the equal parameter method to discretize the knife contact point trajectory line to obtain the knife contact point set, which includes: Set CC i The upper v parameter range is [v min ,v max ], the jth knife contact The length of the curve at j , curvature k j , tangent vector j and normal vector n j It can be expressed and obtained by formula (2), where S u and S v is the tangent vector of the point on the surface in the parameter directions u and v. The discrete CC points are obtained by the equal parameter method, and CC is calculated by formula (3) i Any knife contact point on the table, where n is the discrete number of knife contacts, and so on to find all knife contacts.

8. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 3 is characterized in that: According to step 2.3, obtaining the tool position point and the tool axis vector according to the tool contact point includes: The initial tool position and tool axis vector of any tool contact point in the blade root tool contact trajectory can be calculated by formula (4), where the rake angle α is the angle between the tool axis vector T and the surface normal vector, and θ is the rotation angle around the surface normal vector.

9. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 4, characterized in that: The step 3.1 of establishing the C space and the tool axis space of the tool contact point includes: C space is a two-dimensional plane space with the rake angle as the horizontal coordinate and the rotation angle as the vertical coordinate. The C space is discretized with the rotation angle Δθ and the rake angle Δα. Each point represents a combination of the rake angle and the rotation angle. A tool axis vector can be defined by equation (4). According to the discrete points in C space, a hemispherical tool axis three-dimensional space can be constructed. The center of the circle is the tool position point. The vector to the grid point on the sphere can be calculated by substituting the discrete points in C space into equation (4). When machining a single blade, only the collision interference between the tool and the base plate is considered when machining the blade root area. The inspection area corresponds to the rake angle interval [0°, 90°] in C space.

10. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 4, characterized in that: The step 3.2 projects the tool axis vector and calculates the interference detection area on the base plate, including: Knife contact The tool axis to be measured in the initial tool axis space T(α k ,θ k ) as an example, calculate the tool axis T(α k ,θ k ) In the area where interference may occur on the blade bottom plate, in order to improve the efficiency of interference detection, the tool is moved in the row spacing direction Y L Perform projection and calculate the projection area on the base plate as the interference detection area F. First, use u and v parameter lines at equal intervals to obtain the parameter bounding box of area F. Then use equal parameters to divide the projection area F. Use Δu and Δv as equal parameter intervals to divide the projection area. The intersection of every 4 u and v parameter lines constitutes a parametric surface.

11. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 4, characterized in that: The interference detection between the bottom plate projection area and the tool axis vector in step 3.3 includes: Take the surface S on the projection area F m,n For example, given the tool axis T(α k ,θ k ) interference detection calculation process. The essence of interference detection is to compare the tool axis vector to the surface S m,n The minimum distance d min and the tool radius R, if d min <R, then interference occurs. If d min >R, then no interference occurs. The discrete surface set {S m,n }, where m and n are the discrete numbers of the parameters u and v directions respectively. In order to improve the calculation efficiency, the surface S m,n The 4 parameter vertices replace S m,n Calculate the distance, the tool axis to be measured T(α k ,θ k )The detailed process of interference detection calculation is as follows: {S i,j }={(u i ,v j ),(u i ,v j+1 ),(u i+1 ,v j+1 ),(u i+1 ,v j )}{i,j=1,2,3.....n}(5) Step 3.3.1 Calculate T(α k ,θ k ) and surface S m,n Parameters: distance d(p2) from vertex p2 Surface S m,n The four parameter vertices are p1(u m ,v n )、p2(u m ,v n-1 )、p3(u m-1 ,v n-1 )、p4(u m-1 ,v n ), with the parameter vertex p2(u m ,v n-1 ) as an example, calculate the distances between the tool axis and the parameter vertices p1, p2, p3, and p4 respectively. First, connect point p2 (u m ,v n-1 ) and knife point Forming vectors The vector is calculated by formula (6): With the tool axis T(α k ,θ k ) and the angle β, by substituting β into equation (7), we can calculate p2(u m ,v n-1 ) and the distance d(p2) between the tool axis. Similarly, the distances between the tool axis and the remaining parameter vertices p1, p3, and p4 are calculated. The minimum distance d is obtained by equation (8): min , as the tool axis T(α k ,θ k ) and surface S m,n distance; d min ={d(p1),d(p2),d(p3),d(p4)}(8) Step 3.3.2 Determine the tool axis T(α k ,θ k ) Whether interference occurs For the tool axis T(α k ,θ k ) and surface S m,n The distance d min , if d min >R, satisfying the non-interference condition, the tool axis vector T(α k ,θ k ) and surface S m,n No interference occurs. Similarly, the next surface S is judged m,n+1 , until the tool axis vector T(α k ,θ k ) and the surface set {S m,n } have no interference, if d min <R, indicating that there are parameter vertices and tool axis vector T(α k ,θ k ) produces interference, and the next tool axis vector T(α k+1 ,θ k+1 ), and similarly judge T(α k+1 ,θ k+1 ) whether interference occurs until the knife contact point is determined All tool axis vectors to be measured in the initial tool axis space; T(a k+1 ,i k+1 )=T(α k +Da,i k +Δθ)(9) The knife contact The tool axis vectors to be measured are placed in the interference vector set and the set of non-interference vectors Plotting Points Interference-free tool axis space.

12. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 4, characterized in that: The step 3.4 of interference correction and establishing the non-interference tool axis space of the tool contact point includes: Knife contact Interference tool axis set Taking the interference vector T0 as an example, the tool axis is corrected for the interference vector T0. The corrected tool axis vector T1 does not have interference conditions and is placed in the non-interference vector set. The detailed correction calculation process is as follows: Step 3.4.1 T0 is the interfering tool axis vector that needs to be corrected, and T1 is the corrected non-interfering tool axis vector, where d min is the surface S calculated in step 3.3.1 m,n The shortest distance to the tool axis, R is the tool radius of the ball-end tool, and the theoretical minimum correction distance Δd can be calculated by formula (10): min ,vector The angle β with the tool axis vector T0 is obtained by formula (6), and the required theoretical minimum correction angle γ can be calculated by formula (11), and then jump to step 3.4.2; Δd min =R-d(10) Step 3.4.2 Step 3.4.1 Calculate the theoretical minimum correction angle γ from the interference tool axis T0 to T1. When d min = R, theoretically, the tool is tangent to the blade bottom plate, but the tool axis T1 cannot be used directly for actual processing, and the safety distance d is increased. s , re-correct the position of the tool axis vector T1. The safety distance correction means the correction from the interfering tool axis vector T0 to the theoretical tangent tool axis vector T1, and then from the tangent tool axis vector T1 to the safety tool axis vector T2. The corresponding surface S m,n Distance from d min Correct to distance R, then correct to safe distance R+d s ; The corresponding angle is corrected from β to β+γ+δ, which can be calculated by formula (12). The corrected tool axis vector T2 meets the non-interference condition at this point; Step 3.4.3 Bring the tool axis vector T2 corrected by the safety distance back to step 3.3 to re-check the interference. After determining that no interference occurs, project the tool axis T2 with the fore-tilt angle and rotation angle to obtain the corrected point The non-interference tool axis space, with any interfering tool axis vector For example, after interference correction, the theoretical correction angle is γ, and the new tool axis vector is obtained. After adding the safety distance, the correction angle changes to γ+δ, and the new tool axis vector is 13. The method for generating interference-free smoothing tool paths for five-axis CNC machining of blade root areas according to claim 5, characterized in that: Step 4 generates a non-interference smoothing tool path in the blade root area: Step 4.1 Knife axis vector Representative knife contact All non-interfering tool axis vectors in the tool axis space, the starting tool axis vector is As an example, substitute into formula (4) to calculate the tool axis The forward tilt angle As the starting rake angle of the smoothing tool path; Step 4.2 Search for knife contact points on both sides and The non-interference tool axis vector with the minimum change angle is used to calculate the tool contact point using step 3.3 and No interference tool axis and Use formula (4) to calculate the corresponding inclination and Then, the set is calculated by formula (13) and and The minimum change in inclination angle Δα is calculated by formula (14): min , the minimum Δα will be obtained min Angle and Substitute into formula (4) and calculate the knife contact points The knife axis vector Insert the starting knife axis as Tool path vector collection middle; Step 4.3 continues to iterate on both sides. If the knife contacts It is exactly at the midpoint of the i-th line of tool path. Repeat steps 4.1 and 4.2 to calculate the i-th line of smooth tool path vector Jump to step 4.5, otherwise go to step 4.4; Step 4.4 If the knife contacts It is not the midpoint of the i-th line of tool path. Repeat steps 1 to 3. Finally, there will be a single-side tool contact point remaining. Take the tool axis vector of the left tool contact point as an example. After the iteration on both sides, only the tool contact point remains in the i-th tool path. Without smoothing, the smoothing tool axis vector on one side is calculated by equations (15) and (16), and the minimum Δα is obtained. min Angle and Substitute into formula (4) to calculate the knife contact point The knife axis vector Add to Smooth Vector Collection Similarly, obtain the complete i-th row smoothing optimization tool path vector Step 4.5 Steps 4.1 to 4.4 have calculated The smoothing tool path of the starting tool axis Similarly, we calculate The smoothing tool path of the starting tool axis Step 4.6 Smooth all tool paths in row i Substitute them into formula (17) to calculate the angle variance value of each smooth tool path and put them into the variance set {ν k },in is the corresponding angle of the starting tool axis vector of different smoothing tool paths; In order to reduce the vibration of the machine tool during processing and extend the service life of the tool, the variance set {ν k }minimum variance in The smoothing tool path is the processing tool path. It can be calculated by (18).

14. A terminal, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for generating interference-free smooth tool paths in five-axis CNC machining of a blade root area as described in any one of claims 1 to 13.

15. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for generating interference-free smooth tool paths in five-axis CNC machining of a blade root region according to any one of claims 1 to 13 is implemented.

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